Depression can be induced in a bonnet macaque infant.

Depression is a well-known reaction to separation in all species of macaques studied except the bonnet (M. radiata), in whom this reaction has never before been observed. We have produced the depressive response of postural collapse and social withdrawal in a bonnet infant by altering the social structure of the group in which it lived in a way calculated to interfere whith the species-typical system of social support.     

Brain-derived cells can be infected with HIV isolates derived from both blood and brain.

HIV type 1 and 2 isolates derived from brain and blood of infected individuals were used to infect astrocytic cells of tumor origin. Infection was monitored by polymerase chain reaction. The majority of the isolates infected the glioma cells, independently of the source of isolation. Added to the fact that the majority of primary HIV isolates infect cells of the monocyte/macrophage lineage, these results indicate that primary blood and brain HIV strains have similar target cells. The production of virus from infected astrocytes was detected only upon infection with two macrophage-adapted strains. Also in this case, the number of infected cells was very low and only one in 5000 cells carried the proviral HIV genome.     

Reactions to hidden agents in foods and drugs can be serious.

Agents used to color, flavor, preserve or identify medication frequently used in the treatment of allergic diseases may in themselves produce severe allergic or toxic reactions. Some cross-react with Aspirin. Aminopyrine, Indomethacin (indocin), Mefensmic Acid (ponstel) to which an allergic patient may be sensitive. Three case reports are presented.     

CD4+ NK cells can be productively infected with HIV, leading to downregulation of CD4 expression and changes in function

NK cells mediate the innate immune response, and HIV-infected individuals demonstrate altered NK cell phenotype and function. We find that CD4+ NK cells are susceptible to HIV infection; this could account for the NK cell dysfunction seen in HIV-infected individuals. CD4+ NK cells express CXCR4 and can be infected with X4-tropic viruses and some primary R5-utilizing viral isolates. Treatment with the CXCR4 ligands AMD3100 and SDF-1α partially blocks infection with X4-tropic virus, treatment with anti-CCL Igs upregulates CCR5 surface expression and enables infection with HIV-Bal. HIV infection of NK cells results in CD4 downregulation and the production of infectious virus. HIV-infected CD4+ NK cells mediate NK cell cytotoxicity, however, HIV infection is associated with decreased chemotaxis towards IL-16. Thus, HIV infection of CD4+ NK cells could account for the NK cell dysfunction observed in HIV-infected individuals. Furthermore infected NK cells could serve as a viral reservoir of HIV in vivo.     

Toxoplasmosis can be a sexually transmitted infection with serious clinical consequences. Not all routes of infection are created equal

Toxoplasma gondii infects about 30% of the human population. Common sources of infection are oocysts in cat faeces contaminating drinking water or unwashed vegetables, undercooked meat containing tissue cysts, and organ transplants from infected donors containing tissue cysts. However, very often, it is not possible to identify any potential source of infection in mothers of children with congenital toxoplasmosis. Here we present a hypothesis suggesting that toxoplasmosis is transmitted from infected men to noninfected women during unprotected sexual intercourse, which can result in the most serious form of disease, congenital toxoplasmosis. Arguments for the hypothesis: (1) Toxoplasma tachyzoites are present in the seminal fluid and tissue of the testes of various animals including humans. In some species infection of females by artificial insemination with semen from infected males has been observed. (2) Up to two thirds of Toxoplasma infections in pregnant women cannot be explained by the known risk factors. (3) Prevalence of toxoplasmosis in women in child-bearing age covaries with the incidence of sexually transmitted diseases in particular countries. (4) In some countries, an increased incidence of toxoplasmosis has been reported in women (but not men) aged 25–35 years. This second peak of infection could be associated with women having regular unprotected sex after marriage. (5) Toxoplasmosis triggers schizophrenia in predisposed subjects. Onset of schizophrenia is about 2–3 years earlier in men than in women. However, this difference in the onset can be found only between Toxoplasma-infected patients. The increased onset of schizophrenia in infected women could be associated with the already mentioned second peak of toxoplasmosis incidence. (6) The prevalence of toxoplasmosis decreases in developed countries in last 20 years. This trend could be a result of decrease in promiscuity and increase in safe sex practices, both associated with the AIDS pandemics. (7) In women, probability of being Toxoplasma-infected correlates positively with the amount of unprotected sex with the child’s father before the conception. Evidence against the hypothesis: Questionnaire study showed negative association between Toxoplasma infection and the number of earlier partners with whom the woman had unprotected sex. If our hypothesis turns out to be true, then sexual route of transmission, even if rare, could be responsible for a large part of cases of congenital toxoplasmosis. Women should be warned that having unprotected sex with men of positive or unknown toxoplasmosis status should be avoided during pregnancy.     

Seminal plasma can be a predictive factor for male infertility

Seminal plasma from ejaculates of 10 healthy, fertile volunteersand 63 infertile males was analysed for superoxide dismutase(SOD) and xanthine oxidase (XO) activities using a chemiluminometer.There was no statistically significant difference in the activityof either enzyme between control and infertile populations (113±74 IU/ml for SOD and 1.17 ± 0.52 IU/l for XO) in samplesfrom normozoospermic ejaculates. Sperm progressive motilitywas positively correlated with SOD activity in seminal plasmaof corresponding ejaculates (P < 0.05) and negatively withXO activity (P < 0.001). An ‘oxido-sensitive’index was defined as the SOD/XO ratio and was found to be inverselyrelated to sperm progressive motility samples (P < 0.01).Analysing this index among all tested samples of semen includingthose with pathological spermiograms, as well as normospermic(N) samples we found statistically significant (elevated) differencesin oligoasthenoteratospermia (OAT) in comparison with N (P <0.05); OAT samples were also significantly different from oligospermic(O) and oligoteratospermic (OT) samples (P < 0.05). Thissuggests that the ‘oxido-sensitive’ index of seminalplasma may be a simple diagnostic factor, useful in the determinationof male infertility.     

Tolerance can be infectious

Studies focused on the goal of eliciting transplant tolerance led Herman Waldmann to rejuvenate discarded ideas of 'suppressor T cells'. Such cells are now known to exist.     

Dysplasia can be a pain in the gut

In the gastrointestinal tract, the term 'dysplasia' is used to refer to non-invasive neoplastic epithelium. Although we recognise adenomas of the gut as dysplastic, we don't use the term 'dysplasia' in reporting them. The use of the term 'dysplasia' for pre-invasive epithelium gradually came to replace other terms in studies attempting to identify epithelial changes that were cancer precursors in surveillance biopsies of patients with chronic colitides. The two-tier system of classification, dividing dysplasias into low-grade or high-grade lesions is conceptually straightforward; however, difficulties exist in the distinction of regenerative epithelium from low-grade dysplasia, of low-grade from high-grade dysplasia, and in identifying superficially invasive carcinoma in a dysplastic mucosa. The category 'indefinite for dysplasia' is an honest recognition of the difficulties in distinguishing reactive or regenerative epithelium from low-grade dysplasia, since these epithelia share many cytological features. In surveillance biopsies in ulcerative colitis and Barrett's mucosa, for each epithelial category from non-dysplastic through indefinite, low-grade and high-grade dysplasia, there are specific management recommendations that vary from no change in surveillance to increased surveillance to definitive therapy that is often a major resection. The recommendation for referral of high-grade dysplasias to consultants reflects the concern pathologists have about making such clinically significant diagnoses with limited experience. Pathologists should use the accepted terminology, share cases to expand their experience, and seek consultation in selected cases. This paper follows the evolution of the dysplasia concept, details the difficult areas of diagnosis, and discusses the importance of interaction between clinicians and pathologists in dealing with dysplasias.     

Testing for HIV antibodies should be offered on a same-day basis

We review our experience of testing over 22 000 patients who requested HIV antibody results on a same-day basis. We find that such a service can be provided without compromising the quality of laboratory work or increasing the cost per test. This service is popular with patients, who appear to contain high risk individuals because 2·8 were shown to be HIV-positive. By reducing bureaucratic hurdles, same-day testing clinics may encourage people to come forward for HIV testing and provide a means of offering chemotherapy (directed either at HIV itself or at opportunistic infections) without delay. We thus argue for the proposition.Copyright © 1998 John Wiley & Sons, Ltd.     

Age at which HIV infection can be detected in infants: place of the Yakovlev model

The Yakovlev parametric cure rate model was used to study the age at which HIV-1 infection can be detected in nonbreast-fed infants and the independent predictors of transmission. Blood samples from 145 HIV-1-negative at birth infants born to HIV-1-positive untreated mothers were tested until 15 months. The age at actual detection and at potential detection providing daily tests was studied. The former was described using the Yakovlev model, and the cumulative probabilities of detection along time were calculated. Comparison of observed and predicted delays to positivity revealed the best representation of the age at which HIV becomes detectable among 8 Yakovlev models. Cumulative positive tests were as follows: 3 at 7 days, 10 at 15 days and 1 month, 17 at 3 months, and 18 at 15 months. The log-logistic model was the best-fitting one. The probability of onset of HIV-1 detectability was maximal at day 4. The mean and median age at which HIV becomes detectable were 12 and 6 days, respectively. Maternal CD4(+) cell count was associated with the risk of contamination [hazard ratio of low vs. high count 2.44; 95% (confidence interval): 1.15-6.67]. The model may explain HIV viremia dynamics and define the optimal antiretroviral regimens before randomized trial confirmation.     

Leptin in sperm analysis can be a new indicator

Purpose Radiotherapy, chemotherapy, various tumors and invasive surgery can result in ejaculatory dysfunction and testicular insufficiency. Sperm cryopreservation is the only method which can provide a baby for couples. Cryopreservation freezes tissues and cells, allowing them to be stored for future use by stopping all biological activities. Cryopreservation can cause some harmful changes in the structure and function of the sperm. Leptin molecule plays many roles in most biological processes including the satiety and cell renewal, proliferation, angiogenesis, modulation of energy expenditure and regulation of the neuroendocrine system. Leptin was also reported to be associated with spermatogenesis in several studies. Methods This study aims to use leptin molecule as a parameter for sperm motility and DNA fragmentation before and after the cryopreservation. In this study, semen samples were taken from 30 normospermic male volunteers. Each semen sample was examined for the same parameters before and after the cryopreservation. Samples were analyzed before and after cryopreservation in terms of sperm motility by morphological sperm analysis with spermac stain dye, DNA fragmentation by TUNEL assay, ultrastructural analysis with transmission electron microscopy (TEM), seminal leptin levels by ELISA method and reactive oxygen species (ROS) levels by colorimetric method. Results Decreased sperm motility, distribution of sperm morphology and increased DNA fragmentation were determined after cryopreservation. Similarly, seminal ROS and leptin levels were also increased significantly. There was a negative correlation between seminal leptin and sperm motility. Additionally, there was a positive correlation between seminal leptin and DNA fragmentation. Conclusion According to these results, leptin molecule can be used as a marker for sperm motility and DNA fragmentation before and after cryopreservation. We think that the results of this study can contribute to further studies in the clinical aspect.     

Under-nutrition in older people: a serious and growing global problem!

Everyone agrees that adequate nutrient intake is important to all living things. Without food or water, life on earth would cease to exist. In the field of medical health, some gains have been made in meeting maternal and child nutritional needs. There is great community awareness regarding the importance of meeting the nutritional needs of the developing foetus and child. Malnutrition secondary to decreased intake in older people and weight loss is also a serious problem with unfortunately, very little notice from the community at large. As one ages, several physiological processes may contribute towards the development of protein energy malnutrition. Under-nutrition in older people is sadly far too common, even in developed countries. It is very likely that the same concerted effort used to address child malnutrition is required to combat under-nutrition in our elders. Protein energy malnutrition in older people comes at a significant cost to the individual, families, communities and the healthcare system. Failure to address this syndrome is not only unethical and unhealthy, but also costly. Vigilance and community awareness is important in ensuring that this important syndrome is detected and managed appropriately. This review mainly attempts to describe the pathophysiology, prevalence and consequences of under-nutrition and aims to highlight the importance of this clinical syndrome and the recent growth in our understanding of the processes behind its development. Some management strategies are also briefly described.