Seminal Fluid and the Expression of MHC Class I Antigens in the Placenta of the Rat

PROBLEM : To determine whether seminal fluid influences the expression of MHC class I antigens on the surface of basal trophoblast cells in the placenta of the rat. METHODS : Transfer of DA × DA embryos into a WF (allogeneic) or DA (syngeneic) recipient made pseudopregnant by hormonal treatment followed by mating with a vasectomized male (seminal fluid) or by mechanical stimulation (no seminal fluid). Antigen expression was determined by electron microscopic immunocytochemistry using the appropriate gold-labeled monoclonal antibodies. RESULTS : Seminal fluid did not affect the expression of MHC class I antigens on the surface of the basal trophoblast in either allogeneic or syngeneic matings. CONCLUSIONS : The suppression of the expression of paternal class I antigens on the surface of the basal trophoblast cells in allogeneic pregnancies most likely occurs at the genome level shortly after fertilization.     

Prazosin-induced Blockade of Extraneuronal Uptake Facilitates Dopaminergic Modulation of Muscle Twitches in Rat Vas Deferens

Preliminary findings in our laboratory have shown that prazosin augmented the inhibitory effects of dopamine on the electrically-evoked muscle twitches in rat vas deferens. In this study, we opted to investigate the underlying mechanism and whether a prazosin-induced blockade of extraneuronal uptake process may be involved. Cumulative additions of dopamine (1.8 times 10^?7-4.4 times 10^?5m) elicited slight (<30%) but dose-related inhibition of electrically-evoked (0.05 Hz, 1 ms duration and supramaximal voltage) muscle twitches of the vas deferens. Pretreatment with cocaine (10 μm), prazosin (50 nm) or oestradiol (10 μm) produced comparable potentiation of the inhibitory responses of dopamine; the pD₂ values to dopamine amounted to 4.47 ± 0.20, 4.72 ± 0.21 and 4.56 ± 0.19, respectively. A lower concentration of prazosin (5 nm) failed to alter dopaminergic responses. Further potentiation of dopamine responses was demonstrated in tissues preincubated with a combination of cocaine plus prazosin (50 nm), or cocaine plus oestradiol (pD₂, 5.40 ± 0.11 and 5.42 . 0.05, respectively). However, a mixture of all three drugs failed to elicit any further increase in dopamine responses, a finding that may suggest an extraneuronal uptake blocking activity for prazosin. Inhibition of muscle twitches evoked by bromocriptine, a dopaminoceptor agonist which is not a substrate for extraneuronal uptake, was not affected by prazosin (50 nm) pretreatment. The findings presented in this study emphasize the role of dopamine in modulating noradrenergic neurotransmission in rat vas deferens. More importantly, the results suggest that prazosin may act to block the extraneuronal uptake at noradrenergic sites, an effect that may account for its capability to facilitate dopaminergic modulation of noradrenergic neurotransmission.     

Can mothers identify malnutrition in their children?

To assess mothers' perceptions about malnutrition and theirability to identify malnutrition in their own children, 339children aged 3–35 months and their mothers were studiedin two urban hospitals in Dhaka, Bangladesh, and in a communityclinic. The weight, height, and mid-upper arm circumferenceof the children were measured, and their mothers were interviewed.Child nutritional status according to their mother's statementand anthropometrically assessed nutritional status were compared.Sixty per cent of the mothers correctly identified better nutritionalstatus (weight/age >75% of NCHS median) and 67% mothers correctlyidentified malnutrition (weight/age < 75% of NCHS median)in their children. Sixty-one per cent of mothers with less than5 years of formal education correctly identified better nutrition(weight/age >75%) whereas 38% mothers with more than 5 yearsof education correctly identified better nutrition. Correctidentification of malnutrition was made by 70% of mothers withless than 5 years of formal education, and 74% of educated mothersdid the same. As regards causes of malnutrition, 33% of mothers stated thatlack of food at home resulted in undernutri-tion in their children(mean weight-for-age of these children was 65% of the NCHS median).Mothers' suggestions for improving child health were: betterfood in 31% cases; treatment of illnesses in 22% cases; andboth in 42% cases. The results suggest that most of the mothersare able to identify malnutrition in their children, and 95%of them are aware of ways to improve it, and that the provisionof adequate food and health care may improve child nutritionalstatus.     

A Study of Gastric Cancer in Egypt

Since stomach cancer is rare in Egypt, a study was conductedto try to determine the factors responsible for the low incidence.The study included epidemiological and pathological informationon 55 cases of stomach cancer collected from 1970 to 1977, representing0.33% of the admissions for malignancy in this period. Featuresof the Egyptian diet that could be behind the low incidenceare presented.     

Hepatoprotective Effects of the Shark Bile Salt 5{beta}-Scymnol on Acetaminophen-Induced Liver Damage in Mice

The hepatoprotective effect of the shark bile salt 5ß-Scymnolhas been studied in the model of acute hepatotoxicity inducedby administration of acetaminophen (APAP, paracetamol). 5ß-Scymnolat doses of 20, 35, and 70 mg/kg intraperitoneally (ip) decreasedsignificantly the serum activity of alanine aminotransferase,sorbitol dehydrogenase, and lactate dehydrogenase (p < 0.05)caused by APAP treatment (350 mg/kg ip) alone. The highest doseof 5ß-Scymnol remained hepatoprotective when administered4 hr after the APAP overdose. N-Acetylcysteine (NAC) is protectiveagainst APAP-induced hepatotoxicity at 250 and 500 mg/kg (ip)when administered up to 3 hr after APAP overdose, as shown bya significant reduction in serum enzyme activity. Coadministrationof 5ß-Scymnol (70 mg/kg) and NAC (250 mg/kg) alsoreduced serum enzyme levels and histopathological effects; however,a similar level of hepatoprotection was conferred by 5ß-Scymnoltreatment alone. In addition, 5ß-scymnol has potenthydroxyl radical quenching activity as it markedly inhibiteddeoxyribose degradation in a ferrous/ascorbate Fenton reactionsystem. These results indicate a possible role for the use of5ß-scymnol, either alone or concomitant with NAC,in the prevention of hepatic necrosis following toxic dosesof APAP.     

FAMILIAL CONTINUAL SKIN PEELING

SUMMARY.— Four of 9 siblings in a family are described in whom there is a non-seasonal continuous peeling of the skin. This is not accompanied by any other symptoms or signs. Histological, autoradiographic and electronmicroscopic studies reveal hyperkeratosis rich in -SH and a rapid rate of proliferation of the epidermal cells.     

PRIMARY LOCALIZED MACULAR, CUTANEOUS AMYLOIDOSIS: HISTOCHEMISTHY AND ELECTRON MICROSCOPY

SUMMARY.— Six cases of macular cutaneous amyloidosis are reported. The dermatosis has been defined clinically, histologically, histochemically and ultrastructurally. It, like lichen amyloidosus, is a form of primary localized cutaneous amyloidosis. This variety occurs mainly in females and predominantly as pruritic plaques on the back, which are hyperpigmented, reticulated, macular, occasionally finely papular. The disorder enjoys a world-wide distribution.