Problematic Gaming during COVID-19 Pandemic: A Systematic Review, Meta-Analysis, and Meta-Regression

The COVID-19 pandemic led to government measures enforcing isolation in order to mitigate the spread of the virus. Consequently, online activities, including gaming, increased during this challenging period. Thus, it was possible that problematic gaming (PG) patterns also increased. In this systematic review and meta-analysis, we estimated the prevalence of PG during the COVID-19 pandemic and examined differences among subpopulations. The evaluation of 38 studies revealed that the overall prevalence of PG during the COVID-19 pandemic was 3.6%. Furthermore, higher PG scores were found in undergraduate and gamer subpopulations, as well as in studies using the Gaming Addiction Scale. Finally, meta-regression analyses suggest that stricter government measures, as identified by the Government Stringency Index, may have contributed to a lower prevalence of PG behaviors. A potential explanation of this finding is that containment measures had a protective function with respect to emotional distress, and thus towards PG; alternatively, it could be that current measures for PG become less precise if an individual's functioning is already impaired due to other reasons, such as COVID-19 restrictions. Further theoretical, methodological, and practical implications of the findings are discussed.

Longitudinal Findings on the Oneiric Activity Changes Across the Pandemic

Purpose

COVID-19 pandemic waves have strongly influenced individuals' behaviors and mental health. Here, we analyzed longitudinal data collected in the Spring 2020 and 2021 from a large Italian sample with the aim of assessing changes in dream features between the first and third wave. Specifically, we evaluated the modifications of pandemic dream activity as a function of the general distress variations over time. Also, we detected the best explanatory variables of nightmare frequency and distress.

Materials and Methods

Participants previously involved in the web survey during the first wave of the pandemic were asked to complete a new online survey on sleep and dream features available in Spring 2021 (N=728). Subjects decreasing their level of psychological general distress in the third (T3) vs the first (T1) pandemic wave were defined as "Improved" (N=330). In contrast, participants with an unchanged or increased level of general distress were defined as "Not Improved" (N=398).

Results

Statistical comparisons revealed that dream recall frequency, nightmare frequency, lucid dream frequency, and emotional intensity show a reduction in T3 than T1. Moreover, the Improved group is characterized by lower nightmare rate and nightmare distress than Not Improved people. Our findings confirmed that beyond the trait-like variables (ie, age, sex), specific sleep-related measures are related to nightmare features. In particular, poor sleep hygiene was one of the best determinants of nightmare distress among Not Improved subjects.

Conclusion

Our findings revealed that people experienced an adaptation to the pandemic during the third wave. We also strengthen the notion that nightmares and their variations over time are strongly related to human well-being, suggesting that specific trait-like and sleep-related factors could modulate the relationship between mental health and nightmare features.

Simulation of pandemics in real cities: enhanced and accurate digital laboratories

This study develops a modelling framework for simulating the spread of infectious diseases within real cities. Digital copies of Birmingham (UK) and Bogotá (Colombia) are generated, reproducing their urban environment, infrastructure and population. The digital inhabitants have the same statistical features of the real population. Their motion is a combination of predictable trips (commute to work, school, etc.) and random walks (shopping, leisure, etc.). Millions of individuals, their encounters and the spread of the disease are simulated by means of high-performance computing and massively parallel algorithms for several months and a time resolution of 1 minute. Simulations accurately reproduce the COVID-19 data for Birmingham and Bogotá both before and during the lockdown. The model has only one adjustable parameter calculable in the early stages of the pandemic. Policymakers can use our digital cities as virtual laboratories for testing, predicting and comparing the effects of policies aimed at containing epidemics.

Clinical, histological, and ultrasound follow-up of breast reconstruction with one-stage muscle-sparing "wrap" technique: A single-center experience

BACKGROUND

Prepectoral implant placement and complete coverage with porcine acellular matrix after mastectomy is a new concept in breast surgery presented in few cases in the literature. This paper aimed to present our single-center experience in one-stage breast reconstruction muscle-sparing "wrap" technique by evaluating clinical and aesthetic outcomes, ultrasound and histological examination, and patient quality of life.

METHODS

From January 2014 to January 2017, 52 patients (40 unilateral, 12 bilateral) underwent one-stage muscle-sparing breast reconstructions with Braxon^® acellular dermal matrix and implant. In 3 patients, a surgical biopsy and histological examination with immunohistochemical analysis of the periprosthetic tissue were performed. All patients underwent breast ultrasound examination, and the occurrence of capsular contracture was assessed through the Baker classification and by measuring the mammary compliance scores with the Antoon Paar Mammary compliance system. Breast appearance was evaluated using a visual analogue scale (VAS) and in terms of quality of life using the EOCRT QLQ C-30 and QLQ BR-23 questionnaires.

RESULTS

Early and late postoperative complications are reported. Histological and ultrasound evaluation showed a complete integration of the matrix. According to the VAS scale, the EOCRT QLQ C-30, and QLQ BR-23, patients' satisfaction resulted in a high score in terms of quality of life and aesthetic outcomes.

CONCLUSION

The results of this new surgical technique in selected cases are promising in terms of effectiveness and low rate of postoperative complications, but further long-terms evaluations are required.

Efficacy and Toxicity of Long-Term Administration of 2′,3′-dideoxycytidine in the LP-BM5 Murine-Induced Immunodeficiency Model

The LP-BM5 murine retrovirus-induced immunodeficiency model was used to evaluate the efficacy and toxicity of long-term 2′,3′-dideoxycytidine (DDC) therapy. A mean plasma drug concentration of 0.2 + 0.02 μm of DDC for 3 months was found to reduce splenomegaly, lymphoadenopathy and hypergammaglobulinemia in infected mice. However, DDC also reduced spleen weight in control mice and spleen haemopoiesis in both infected and uninfected animals. In the bone marrow the most prominent feature of DDC treatment was a marked reduction of megakariocytes, while in the liver an hepatocellular vacuolation was evident in uninfected animals. DDC reduced, but did not prevent, LP-BM5 integration in lymph node DNA and Pr 60gag expression in spleen lymphocytes and bone marrow cells. Furthermore, DDC reduced the mitochondrial DNA content and restored the mitogen proliferation of T cells but not that of B cells in infected mice. Thus, DDC appears to be of some, but limited, efficacy in murine AIDS, with a toxicity profile involving more cell types than previously thought.

Cutaneous melanoma frequencies and seasonal trend in 20 years of observation of a population characterised by excessive sun exposure

Background

Cutaneous melanoma is an aggressive form of skin cancer. It has become an increasingly common neoplasm in the most developed countries, especially among individuals of European origin.

Patients and methods.

Anonymous data of patients with cutaneous melanoma were collected from the diagnostic database of the University Hospital of Trieste from 1 January 1990 to 10 December 2013. Our study is based on a population which was constant over the period of observation; it was also well-defined and characterised by unrestrained sun exposure.

Results

The number of cutaneous melanomas increased during the period of observation with a seasonality trend and gender related differences both for anatomical sites distribution and stage of the disease. Moreover, 6% of our cohort developed multiple melanomas.

Conclusions

In a well-defined population devoted to excessive sun exposure the frequencies of skin melanomas roughly doubled from 1990 to 2013 following a seasonal trend. In that population, prevention efforts according to gender specific risk behaviour, as well as follow-up programmes both for evaluation of metastatic spreading and for early diagnosis of additional skin melanomas, are crucial due to gender specific differences and to the occurrence of multiple melanomas.

Sporotrichoid Mycobacterium marinum infection in an elderly woman

We describe the case of an elderly woman who acquired a Mycobacterium marinum infection following skin exposure to the bacteria through a small wound on her right ring finger, obtained while preparing fish. The resultant sporotrichoid nodules of the right hand and the distal forearm, refractory to the initial therapy with doxycycline and rifampicin, were successfully treated with oral regimen of clarithromycin.

Hyaluronic acid-chondroitin sulfate: a potential factor to select pure stress urinary incontinence in patients with interstitial cystitis⁄painful bladder syndrome and mixed incontinence symptoms

AIM

Aim of the study was to validate the Hyaluronic acid-Chondroitin sulfate (HA-CS) as ex adiuvantibus criteria to identified patients with urgency symptoms related to interstitial cystitis/painful bladder syndrome (IC/PBS) and to obtained a population of patients with pure stress urinary incontinence.

METHODS

We retrospectively analysed clinical data of 17 patients with clinical suspect of IC/PBS, which received intravescical HA-CS to reduce pelvic pain and urgency symptoms waiting for surgical treatment for stress urinary incontinence. The main outcomes were reduction of urinary frequency, urgency, and bladder pain.

RESULTS

Compared to baseline, a significant decrease in pain, urgency and frequency were observed. Of the 17 patients, 82.3% reported resolution of pain and urge symptoms and in patients with persistence of urge symptoms the urodynamic assessment showed an overactive bladder syndrome (OAB).

CONCLUSION

HA-CS treatment induces an improvement in pain and urgency symptoms in patients with IC⁄PBS that referred also stress urinary incontinence. Therefore, HA-CS treatment could be use as clinical adjunctive parameter to select patients with pure stress urinary incontinence.

Employment of higher doses of botulinum toxin type A to reduce spasticity after stroke

Spasticity is a common disabling symptom for several neurological conditions. Botulinum toxin type A injection represents the gold standard treatment for focal spasticity with efficacy, reversibility, and low prevalence of complications. Current guidelines suggest a dose up to 600 units (U) of onabotulinumtoxinA/incobotulinumtoxinA or up to 1,500 U of abobotulinumtoxinA to treat post-stroke spasticity to avoid important adverse effects. However, recently, higher doses of botulinum toxin type A were employed, especially in case of upper and lower limb severe spasticity. With searches of US National Library of Medicine databases, we identified all studies published from December 1989 to July 2014 concerning the use of higher doses of this neurotoxin for spasticity treatment with at least a dose of 600 U of onabotulinumtoxinA and incobotulinumtoxinA or 1,800 U of abobotulinumtoxinA. The cumulative body of evidence coming from the eight studies selected suggested that higher doses of botulinum toxin type A appeared to be efficacious in reducing spasticity of the upper and lower limbs after stroke, with adverse effects generally mild. However, further investigations are needed to determine the safety and reproducibility in larger case series or randomized clinical trials of higher doses of botulinum toxin type A also after repeated injections.

[Use of progesterone-releasing intra-uterine system in menhorragia relapse prevention after laparoscopic myomectomy]

AIM

Abnormal uterine bleeding (AUB) affects about 30% of women in childbearing age with negative impact on patient's quality of life and uterine myomas represent one of the major cause of AUB. Laparoscopic myomectomy has proven to be efficient to reduce uterine bleeding and pelvic pain, but some patients presents postsurgery menhorragia with anemia. To reduce it, the combined use of levonorgestrel releasing intrauterine system (LNG-IUS) positioned at the end of surgery, seems to produce a clinically relevant decrease in AUB with a symptomatology improvement. The aim of this study was to retrospectively evaluate if postsurgery placement of LNG-IUS improves hematological outcomes (hemoglobin and ferritin level) in woman submitted to laparoscopic myomectomy.

METHODS

We retrospectively collected data from 58 women who underwent laparoscopic myomectomy from September 2010 to September 2011. Twenty-six patients were treated by laparoscopic myomectomy followed by LNG-IUS positioning at the end of surgery (Experimental group) and thirty-two patients were treated by surgery alone (Control group). We compared blood hemoglobin and ferritin levels assessed preoperatively, in day one and 6, 12 and 18 months after surgery.

RESULTS

There was a statistically significant improvement in terms of post-surgery hemoglobin and ferritin levels at 6 month follow up (P=0.02 and P=0.002 respectively) and 12 month follow-up (P=0.001 and P=0.001, respectively) in experimental group vs. control group and a positive trend, but not statistically significant, in ferritin levels at 18 month-follow-up (P=0.1).

CONCLUSION

Our data suggest that combined treatment with laparoscopic myomectomy followed by LNG-IUS produces a clinically relevant improvement in hematological values.

Giant melanoma of the abdomen: case report and revision of the published cases

Malignant melanoma presenting as a giant cutaneous mass is rarely observed in clinical practice. A few patients with giant melanoma have been reported, Herein, we document our experience with a patient with giant cutaneous melanoma of the abdomen and review the features of previously reported individuals.

[Sex ratio in the offspring of pregnant women with polycystic ovary syndrome: effect of different phenotypes]

AIM

The aim of this paper was to investigate the sex ratio in the offspring of pregnant patients with polycystic ovary syndrome (PCOS).

METHODS

Analysis of 70 pregnant patients with PCOS who achieve a pregnancy without any kind of treatment, and having as controls 63 healthy pregnant women without any feature of PCOS.

RESULTS

No significant difference in sex ratio was detected between PCOS and controls, even if it resulted significantly different in the full-blown and non-PCO phenotypes.

CONCLUSION

The PCOS phenotypes influenced the sex ratio in the offspring, suggesting that environmental factors could play a role in determination of the offspring gender.

[A retrospective analysis comparing colposuspension and retropubic mid-urethral sling as preventive anti-incontinence measures during laparoscopic sacrocolpopexy]

AIM

The aim of this paper was to compare two anti-incontinence procedures during laparoscopic sacrocolpopexy (LSC) to prevent postoperative stress urinary incontinence (SUI).

METHODS

Retrospective analysis of 90 continent hysterectomized patients with vaginal vault prolapse treated with LSC plus colposuspension (group A, N.=30), LSC plus retropubic mid-urethral sling (group B, N.=30), or LSC alone (group C, N.=30).

RESULTS

De novo SUI rate resulted significantly (P<0.05) lower in group B than C. No difference was detected regarding de novo urge urinary incontinence. Total reoperation rate resulted significantly (P<0.05) higher in group A than B and lower in group B than C.

CONCLUSION

When associated to LSC for preventing SUI, colposuspension and retropubic mid-urethral sling are effective and safe, even if mid-urethral sling seems to provide the best risk/benefit profile.

Immunity to poliomyelitis: situation in northern Italy and in some other European population groups

The aim of the program to eradicate poliomyelitis is expected to be achieved in the space of very few years and therefore, as they approach this goal, countries find themselves faced with various problems to be tackled. Among these is the decision about how and when to stop polio vaccination, which also depends on seroepidemiological evaluations, necessary because of the possible persistence of circulating strains of poliovirus of vaccine origin which might continue even after the suspension of vaccination. For this reason, the results of seroepidemiological surveys carried out in some European countries in different periods of time and on various samples of the population are discussed. Although the status of immune coverage is satisfactory, a few situations of susceptibility were found; these should be better monitored and, if necessary, corrected to guarantee a homogeneous and lasting resistance of the European population towards polioviruses.

Survival ability of cytotoxic strains of motile Aeromonas spp. in different types of water

The ability of motile Aeromonas spp. to survive in drinking water (mineral and tap water) and in sea water was experimentally tested. Clinically isolated cytotoxic strains of A. hydrophila, A. caviae and A. sobria were selected for this study. After contamination of water samples, the survival of Aeromonas strains was studied for at least three months using viable counts. The results obtained show that the survival of the Aeromonas spp. varies considerably depending on species and water type. For all three species, the survival time was longest in mineral water, where viable bacteria of each strain were still detected after 100 d. Moreover, A hydrophila and A. caviae also re-grew on the first day. In tap water all strains showed marked survival, although to a lesser extent than in mineral water. Aeromonas cells showed a rapid decline in sea water (90% reduction in viable cells after about two d) and thus seem to be more sensitive to saline/marine stress than chlorination.

Long-term follow up of a randomized, controlled trial on prophylactic sclerotherapy of small oesophageal varices in liver cirrhosis

BACKGROUND

In order to evaluate the prophylactic impact of sclerotherapy of small varices in patients with cirrhosis and no endoscopic signs suggesting risk of haemorrhage, a randomized clinical trial was performed.

METHODS

Seventy-one hospitalized patients met the inclusion criteria of diagnosis of cirrhosis with no previous bleeding and small varices. Due to exclusion criteria of: gastroduodenal ulcers (n = 5), diverticulosis (n = 1), hepatic insufficiency (n = 10), hepatocellular carcinoma (n = 4), death before randomization (n = 6), age over 70 (n = 1) and denial of consent to participate in the study (n = 1), 43 patients could be randomized, 21 for sclerotherapy and 22 for the control group. Two patients (one in each group) were lost to follow up, and another patient, although not lost, refused sclerotherapy after randomization. Ethanolamine oleate was used as the sclerosing agent. All patients were followed up for a mean time of 60 months, initially every 2 months for the first 2 years and clinical and endoscopic controls were performed each 6-12 months thereafter.

RESULTS AND CONCLUSIONS

During the first 2 years clinical assessment showed that there were five bleedings in the sclerotherapy group and none in the control group, but mortality was similar in both groups. Long-term follow up continued to show a higher prevalence of bleeding in the sclerotherapy group but that mortality was not different from the control group.

Bactericidal effect of chlorine on motile Aeromonas spp. in drinking water supplies and influence of temperature on disinfection efficacy

The susceptibility of toxigenic Aeromonas spp. to free chlorine in drinking water supplies, and the influence of environmental temperature on the bactericidal activity of the oxidant, were evaluated. The results showed inactivation curves characterized by an initial phase of rapid reduction of viable cells followed by a slow inactivation of bacteria. The effect of the chlorine compound was markedly influenced by water temperature. At a summer water temperature (20 degrees C), the efficacy of the chlorine concentrations tested was found to be two to three times lower compared to that found at a winter temperature (5 degrees C). Resistance was moderately, but significantly, greater in Aer. hydrophila vs Aer. caviae and Aer. sobria, but all Aeromonas spp. were more susceptible than Escherichia coli. Selective pressure with free chlorine did not produce Aeromonas cells with higher levels of chlorine resistance.

Acute oxygen supplementation does not relieve the impairment of respiratory muscle strength in hypoxemic COPD

STUDY OBJECTIVES

To verify whether hypoxemia affects respiratory muscle strength in the absence of malnutrition and whether such effect, if present, is reversible with an acute oxygen supplementation.

DESIGN

Case series analysis, before-after trial.

SETTING

Outpatient pneumology departments of two university hospitals.

PATIENTS

One hundred twenty patients affected by COPD in stable conditions having actual to ideal body weight ratio of > or =90%.

MEASUREMENTS AND RESULTS

Maximal inspiratory pressure (MIP) was measured at functional residual capacity level in the whole sample of subjects and during oxygen supplementation in 58 patients having a PaO2< or =60 mm Hg when breathing in room air. Predictors of MIP were assessed by a multivariate analysis. MIP values before and after oxygen supplementation were compared by a paired t test. MIP was independently correlated with FVC (p<0.001), PaO2 (p<0.01), and age (p<0.01). In the subgroup of hypoxemic patients, MIP values did not change significantly after oxygen supplementation (3.08+/-1.74 vs 3.03+/-1.91 kPa, t=0.43, not significant).

CONCLUSIONS

Hypoxemia is an important negative correlate of MIP even in well-nourished COPD patients. Its effect is not reversible with an acute oxygen supplementation.

Virulence factors in Aeromonas spp and their association with gastrointestinal disease

Culture filtrates of eight Aeromonas strains isolated from the feces of 487 subjects (292 diarrhoeic patients and 195 asymptomatic subjects) were tested for toxin production in CHO and McCoy cells, and adhesion and invasive ability in Caco-2 cells. Among these isolates, three Aeromonas sobria and one Aeromonas caviae strains possessed virulence-associated properties. Toxin production was the most common of the three virulence properties. Two A. caviae were associated, in the absence of other diarrhoeagenic agents, with gastroenteritis; however, a virulence marker (cytotoxin) was recognized only in one strain. Two strains of A. sobria isolated from subjects with gastroenteritis were shown to be associated with one (cytotoxicity) or two (adhesion and invasive abilities) virulence factors, respectively. However, a third strain of A. sobria, although cytotoxic and invasive, was isolated from an asymptomatic subject. The results show that Aeromonas spp may act as human enteric pathogens, but also indicate that the significance of several putative virulence factors, such as production of cytotoxin and the capacity to adhere to and invade mammalian cells, remains controversial in explaining the enteropathogenesis of Aeromonads and therefore needs further studies.

Antipoliomyelitis immunity status in a cohort of young men drafted into military service, residing in the suburban Milan area

The aim of this study was to verify the antipolio immune status of a cohort of eighteen year-olds residing in the suburban Milan area for whom vaccination histories were available. Seropositivity (titres of neutralizing antibodies > or = 1:8) for the three virus serotypes was detected in 89.2% of the 530 subjects tested, whereas simultaneous seronegativity for all three polioviruses was found for only 0.6% of the subjects.

[High-dose brachytherapy in endobronchial neoplastic stenoses]

Form March, 1991, to September, 1995, twenty-nine patients with endobronchial neoplastic stenosis were treated with high dose rate (HDR) brachytherapy at the Casa Sollievo della Sofferenza Hospital in San Giovanni Rotondo (Foggia, Italy). Fifteen patients had hemoptysis, 10 dyspnea, 6 constant cough and 6 lung atelectasis. The total dose, specified at 1 cm from the source, ranged 5 to 21 Gy and the fraction doses 5 to 15 Gy. Fourteen of 29 patients (48%) died. The mean survival is 7 months, with the follow-up ranging 1 to 22 months. Subjective responses were achieved in 78.4% of cases, with 67.6% complete and 10.8% partial remission rates. Complete remission of hemoptysis was observed in 100% of patients. Dyspnea improved in 70%, cough in 46.4% and atelectasis in 83.2%. Endoscopic findings, 1 month after the end of brachytherapy, showed a response in 79.4% of patients. The complication rate was 13.8% (1 tracheoesophageal fistula, 2 pulmonary hemorrhages and 1 cavitary necrosis). Even though the number of treated patients is small, our experience confirms the efficacy of HDR endobronchial brachytherapy in the palliation of lung cancer-related symptoms. Literature data show that brachytherapy improves the quality of life in the patients with poor prognosis who are otherwise untreatable. The HDR technique is more accurate than the LDR technique and therapy is better tolerated also because execution time is shorter. Prospective clinical trials are needed to investigate the most effective total doses and fractionations and to better define the role of brachytherapy in the curative treatment of lung cancer.

Comparison of colloidal bismuth subcitrate and metronidazole, both in combination with an H2-antagonist as therapy for Helicobacter pylori

In this random study, the efficacy of either colloidal bismuth subcitrate (CBS) or metronidazole in combination with an H2-antagonist in the treatment of various gastric pathologies was evaluated, along with the trends in antibody levels. Among the 40 Helicobacter pylori-positive patients with various gastroduodenal pathologies who underwent chemotherapy, 27 were treated with CBS and 13 with metronidazole. H. pylori was eradicated in 48.14% of the patients treated with CBS and 53.8% of those treated with metronidazole. After therapy, no statistically significant or slight decrease in the serum levels of antibodies was found.

Increased microbicidal activity of human monoblastoid cells upon long-term exposure to dideoxycytidine

2',3'-Dideoxycytidine (ddC) is a nucleoside analogue currently used in AIDS therapy. We had previously found that long term exposure of U937 human monoblastoid cells to ddC induces the selection of drug-resistant cells (U937-R). In the present work we investigated some important biochemical properties and functional activities of these resistant cells. The results obtained show that U937-R maintained the properties of cell aggregation, adhesion and differentiation. Basal respiration, protein kinase C activity, superoxide anion release and intracellular free calcium were all increased in the drug-resistant line. Phagocytosis of fungi (Candida albicans) and bacteria (Staphylococcus aureus and Salmonella anatum) were similar in U937 and U937-R cells. Killing of C. albicans was significantly higher in drug-resistant cells (29.07 +/- 2.23% of killing vs 19.07 +/- 2.01 in the control; p < 0.001). Similarly, the bacterial killing was enhanced in U937-R cells (34.07 +/- 8.06% vs 22.60 +/- 4.41% in the control; p < 0.05). Thus, the results presented in this paper provide evidence of an increased microbicidal activity of human monocytic cells upon long term exposure to ddC, most likely due to an increased oxidative metabolism.

Action of cystine in the cytotoxic response of Escherichia coli cells exposed to hydrogen peroxide

Cystine markedly enhanced the cytotoxic response of Escherichia coli cells to concentrations of hydrogen peroxide resulting in mode one killing, but displayed little effect in mode two killed cells. The effect of cystine was concentration-dependent over a range of 5-50 microM and did not further increase at higher levels. Cystine had similar effects in other bacterial systems. In order to sensitize the cells to the oxidative injury, the amino acid must be present during exposure to the oxidant since no enhancement of the cytotoxic response can be observed in cystine pre-loaded cells. In addition, no further enhancement of cytotoxicity could be detected when cystine was added before and left during challenge with the oxidant. The enhancing effect of cystine on oxidative injury of E. coli cells appears to be directly mediated by the amino acid and in fact cysteic acid, the most likely oxidation product, had no effect on the killing of bacterial cells elicited by hydrogen peroxide. Other disulfide compounds such as oxidized glutathione, cystamine and dithionitrobenzoic acid only slightly increased the susceptibility of bacteria to the oxidant. The effect of the disulfides was not concentration-dependent over a range of 200-800 microM and was statistically significant only for cystamine. Taken together, these results indicate that cystine markedly increases the cytotoxic response of bacteria to hydrogen peroxide and suggest that the amino acid might impair the cellular defence machinery against hydrogen peroxide. This effect may involve a thiol-disulfide exchange reaction at the cell membrane level.

The bone marrow in murine AIDS

In order to increase the understanding of blood cytopenias in HIV infection we have investigated the bone marrow in murine AIDS. C57BL/6 mice infected with the LP-BM5 retrovirus show a decrease in cellularity, numerous haemophagocytic histiocytes, a reduction of all erythroid precursor cells, an increase in eosinophil number and an increase in lymphocytes. Immunostaining with an anti-Pr60gag antibody shows that the majority of bone marrow cells express the viral protein. Thus, the bone marrow in MAIDS has many similarities with the bone marrow from patients with advanced AIDS and may prove useful as a model for therapy aimed at treating blood cytopenias.

Sexual transmission of hepatitis C virus and HIV-1 infection in female intravenous drug users

We examined the relationship between the presence of antibody to HCV and sexually transmitted diseases in 151 female, intravenous drug users aged 17-43 years. Anti-HCV was present in 49 of 66 HIV-1-negative women (74.2%), and 63 of 85 HIV-1-positive women (74.1%). Anti-HCV seropositivity was significantly related to sexually transmitted infections (Ureaplasma urealyticum infections excluded) in HIV-1-seronegative women, but not in HIV-1-positive women. Also, in HIV-1-negative subjects. Trichomonas vaginalis infections (and infections with M. hominis) were significantly related to anti-HCV seropositivity, and a positive relation between the number of sexual partners and the presence of anti-HCV was demonstrated. In HIV-1-positive subjects a shared use of needles and syringes was more likely, and an increased parenteral exposure to HCV may decrease the relative contribution by sexual transmission. However, in HIV-1-negative subjects, sexual transmission of HCV appears to be both a possible and important means of transmission.

In vitro and in vivo toxicity of 2',3'-dideoxycytidine in mice

3T3 mouse embryo fibroblast cell growth was inhibited in a concentration dependent manner by 2',3'-dideoxycytidine (ddCyd), a strong inhibitor of human immunodeficiency virus. Cell growth inhibition was associated with an increased incorporation of ddCyd into cell DNA. In contrast SP2/0-Ag14 (a mouse myeloma) cell growth is not inhibited by 100 microM ddCyd both in the presence or absence of hypoxanthine and thymidine. Furthermore, in vitro spleen cell proliferation, upon phytohemagglutinin (PHA) addition, was much more affected by ddCyd in C57BL/6 mice than in Swiss albino mice. That indeed ddCyd affects spleen cell proliferation was confirmed by studies on splenocytes obtained from C57BL/6 mice that received ddCyd for 2 weeks in drinking water. These results suggest that ddCyd toxicity in mice is cell and strain dependent and that the toxicity mechanism is related to the incorporation of the drug in cell DNA.

Differential effect of the amino acid cystine in cultured mammalian and bacterial cells exposed to oxidative stress

The effect of cystine in the cytotoxic response of cultured Chinese hamster ovary and Escherichia coli cells to challenge with hydrogen peroxide has been investigated. It was found that this amino acid could either protect or sensitize cells, depending on the cellular system. In fact, although a reduction in the growth-inhibitory effect of hydrogen peroxide was observed in mammalian cells, a marked increase in the susceptibility to oxidative stress was induced by cystine in bacteria. None of the amino acid precursors of glutathione, e.g., glutamate, glycine or cysteine, afforded protection in the mammalian cell system, whereas cysteine, but not glycine or glutamate, markedly sensitized bacteria to hydrogen peroxide-induced cell killing. In mammalian cells, methionine, an amino acid which is converted to cysteine, was also unable to modify the oxidative response. The results presented indicate that cystine displays differential effects in oxidatively injured mammalian or bacterial cells and suggest that the mechanism whereby the amino acid modulates the lethal action of hydrogen peroxide differs in the two cellular systems.

Prevalence of anti-HCV in subjects of various age groups

812 serum samples from 382 males and 430 females from various age groups were examined. All the samples were tested for anti-HCV hepatitis C virus, anti-HBc and HBsAg with an enzymeimmunoassay. The total serum prevalence was 2.9% for anti-HVC, 22.2% for anti-HBc and 4.6% for HBsAg. The seropositivity rates of anti-HCV and anti-HBc tended to increase with age, while for HBsAg a more regular pattern was observed for the different subject groups. The fact that anti-HCV are more frequently found together with HBV markers confirms the existence of similar modes of transmission of the two viruses.

[Cutaneous tumor metastasis. A possible first clinical event of visceral neoplasms]

Two cases of visceral malignant tumours due to cutaneous metastases (stomach adenocarcinoma and left pulmonary adenocarcinoma). Are reported in both cases the cutaneous lesions represent the first clinical phenomenon of the disease.

In vitro toxicity and metabolism of 2',3'-dideoxycytidine, an inhibitor of human immunodeficiency virus infectivity

U937 human monoblastoid cell growth was inhibited in a concentration-dependent manner by 2',3'-dideoxycytidine (ddCyd) (an antiretroviral drug) up to 500 microM. Cell growth inhibition was associated with a pronounced increase in cell volume, however this was not due to cell ATP or NAD+ depletion that could effect osmotic balance or DNA repair. This ddCyd toxicity paralleled the accumulation of ddCyd into acid soluble material where 2',3'-dideoxycytidine-5'-triphosphate (ddCTP) was the predominant labelled nucleotide up to an extracellular ddCyd concentration of 150 microM. At higher ddCyd concentrations, the amount of 2',3'-dideoxycytidine-5'-diphosphate (ddCDP) became predominant over ddCTP. This increase of phosphorylated dideoxycytidine in U937 cells was also associated with an increased incorporation of the drug into cell DNA suggesting a possible toxicity mechanism. That ddCyd does indeed become cytotoxic to human cell by incorporation into DNA was shown by incubating human resting and stimulated lymphocytes with ddCyd. While the drug does not affect cell viability in resting cells it strongly affects cell proliferation upon phytohemagglutinin (PHA) addition.