Developmental morphological analyses on the preglottal salivary gland in Japanese quails (Coturnix japonica)

To understand the development of the mucous preglottal salivary gland in Coturnix japonica (Japanese quail), morphological and histochemical studies were performed on 20 healthy Japanese quail embryos (aging from 10th to 17th incubation days) and 25 healthy quail chicks (aging from 0th to 60th days). The primordia of preglottal salivary gland were observed as an epithelial bud at the early embryonic stage, which then elongated and differentiated into secretory units by the end of this stage. In Japanese quails, the preglottal salivary gland was a mucous polystomatic tubuloalveolar unpaired gland composed of two lateral portions and a middle one embedded into the submucosa of the lingual root. The gland openings accompanied taste pore (8.17 μm) of taste buds associated salivary glands type; some skeletal muscle fibers embedded among secretory lobules extended from muscle cricohyoideus at 14th day-old quail chick. Also, both herbts corpuscles and secretory motor plexus could be detected among secretory lobules. Based on our investigations, the development of the preglottal salivary gland could clearly be distinguished in the embryonic stage into pre bud and bud stages at 10th day old, cord and branching stages ended by cavitation at 11th day old, canalization stage at 13th day old, lobulation and secretory stages by the 17th day old. The secretory materials showed different histochemical reactions ended with highly alcinophilic mucous indicated highly sialomucin (acidic) content. Myoepithelial cells could be demonstrated at a 17-day old quail embryo and thereafter surrounded the secretory endpieces of the preglottal salivary gland.

Association between type 1, type 2 cytokines, diabetic autoantibodies and 25-hydroxyvitamin D in children with type 1 diabetes

PURPOSE

Vitamin D may play a role in the pathogenesis of type 1 diabetes (T1D). The aim of the current study was to determine the possible association between 25-hydroxyvitamin D [25(OH)D] levels and circulating levels of type 1 and type 2 cytokines, as well as the pathophysiology of T1D in children.

METHODS

A total of 250 T1D patients and 250 sex- and age-matched T1D-free controls were screened for 25(OH)D, hemoglobin A1c (HbA1c), type 1 and type 2 cytokines, C-reactive protein (CRP) and bone mineral metabolism, as well as antibodies against insulin, glutamic acid decarboxylase (anti-GAD 65) and islet cells.

RESULTS

Our data showed that the plasma level of 25(OH)D was significantly lower in T1D patients and that there was a significant negative correlation between 25(OH)D levels and HbA1c values. There was a significant association between deficient levels of 25(OH)D and higher levels of cytokines (IFN-γ, TNF-α, IL-6, IL-1β, IL-4 and IL-10) and CRP. Total blood hemoglobin, the hematocrit percentage, body mass index SDS values, phosphate and magnesium levels were significantly lower in T1D patients than in T1D-free subjects. The levels of parathyroid hormone and alkaline phosphatase were significantly higher in T1D patients. Higher levels of cytokines were significantly associated with deficient levels of 25(OH)D. Moreover, in T1D patients, higher levels of islet antibodies, anti-GAD antibodies and anti-insulin antibodies were significantly associated with deficient levels of 25(OH)D.

CONCLUSIONS

In type 1 diabetic children, deficient levels of 25(OH)D are associated with high levels of HbA1c, circulatory cytokines and antibody markers.

Predictive Value of Assessment of Different Modalities in the Diagnosis of Infantile Cholestasis

This study investigated the relative accuracy and roles of abdominal ultrasonography, hepatobiliary scintigraphy and liver biopsy in the diagnosis of infantile cholestasis. A total of 50 infants (27 females) aged 1 − 12 months were classified into those with intrahepatic causes of cholestasis ( n = 22) and those with extrahepatic causes ( n = 28). Cholestasis is caused by a wide range of conditions and diagnosis requires meticulous history taking, thorough clinical examination and many laboratory tests. The most common cause of intrahepatic cholestasis was found to be idiopathic neonatal hepatitis (54.5%), followed by infectious hepatitis (9.1%), metabolic liver diseases (9.1%), intrahepatic biliary atresia (9.1%) and Alagille syndrome (4.5%). The most common cause of extrahepatic cholestasis was extrahepatic biliary atresia (96.4%). The incidence of choledochal cyst was low (3.6%). The cornerstone of the diagnosis of infantile cholestasis was found to be liver biopsy, which was associated with a high degree of accuracy.

Viral hepatitis E outbreak in Al-Sadr city, Baghdad, Iraq

Hepatitis E virus (HEV) is a major cause of acute hepatitis in many developing countries. This study describes an outbreak of HEV infection in Al-Sadr city, Baghdad. Blood samples obtained from patients with jaundice attending 19 primary health care centres in AI-Sadr city during a 6-month period in 2005 were tested for HEV. HEV (IgM) antibodies were detected in 38.1% of 268 patients. The association of HEV infection with unacceptable residual chlorine concentrations and/or bacteriologically unsafe water samples was significant. High rates of HEV infection, low chlorine concentrations and unsafe water were reported in June. Gross isruption of sanitation and water supplies was the most likely contributing factor.

Metoclopramide protection of cholinesterase from paraoxon inhibition

This study evaluated the protective effect of the benzamide compound metoclopramide (MCP) against inhibition by paraoxon (POX) as assessed by red blood cell acetylcholinesterase (RBC-AChE) activity. Three groups of 6 rats each were used. All substances were applied ip daily for 5 d, followed by a 2-d rest. The 7-d cycle was repeated 6 times. Group 1 received 100 nM POX, Group 2 received 50 microM MCP. Group 3 received 100 nM POX + 50 microM MCP. Red blood cell acetylcholinesterase measurements were performed at base line and then after each 7-d cycle. Enzyme activities were compared using the Mann-Whitney rank order test. Metoclopramide conferred significant in vivo protection from inhibition of RBC-AChE by POX.

Paraoxon induces apoptosis in EL4 cells via activation of mitochondrial pathways

The toxicity of organophosphorus compounds, such as paraoxon (POX), is due to their anticholinesterase action. Recently, we have shown that, at noncholinergic doses (1 to 10 nM), POX (the bioactive metabolite of parathion) causes apoptotic cell death in murine EL4 T-lymphocytic leukemia cell line through activation of caspase-3. In this study, by employing caspase-specific inhibitors, we extend our observations to elucidate the sequence of events involved in POX-stimulated apoptosis. Pretreatment of EL4 cells with the caspase-9-specific inhibitor zLEHD-fmk attenuated POX-induced apoptosis in a dose-dependent manner, whereas the caspase-8 inhibitor zIETD-fmk had no effect. Furthermore, the activation of caspase-9, -8, and -3 in response to POX treatment was completely inhibited in the presence of zLEHD-fmk, implicating the involvement of caspase 9-dependent mitochondrial pathways in POX-stimulated apoptosis. Indeed, under both in vitro and in vivo conditions, POX triggered a dose- and time-dependent translocation of cytochrome c from mitochondria into the cytosol, as assessed by Western blot analysis. Investigation of the mechanism of cytochrome c release revealed that POX disrupted mitochondrial transmembrane potential. Neither this effect nor cytchrome c release was dependent on caspase activation, since the general inhibitor of the caspase family zVAD-fmk did not influence both processes. Finally, POX treatment also resulted in a time-dependent up-regulation and translocation of the proapoptotic molecule Bax to mitochondria. Inhibition of this event by zVAD-fmk suggests that the activation and translocation of Bax to mitochondria is subsequent to activation of the caspase cascades. The results indicate that POX induces apoptosis in EL4 cells through a direct effect on mitochondria by disrupting its transmembrane potential, causing the release of cytochrome c into the cytosol and subsequent activation of caspase-9. Inhibition of this specific pathway might provide a useful strategy to minimize organophosphate-induced poisoning.

Increase in neuronal nitric oxide synthase content of the gastroduodenal tract of diabetic rats

This study examined the changes occurring in the pattern of distribution and expression of neuronal nitric oxide synthase (nNOS)-positive nerves in the gastroduodenal tract of streptozotocin-induced diabetic rats. The ganglion cells of the myenteric plexus of the gastric antrum of normal rats contain nNOS. We also observed nNOS-positive neurons and fibres in the myenteric plexus of the duodenum of normal rats. After the onset of diabetes, the number and intensity of staining of nNOS-positive nerve profiles in the gastric antrum and duodenum did not change significantly. However, Western blotting showed a significant increase in the expression of nNOS after the onset of diabetes. In conclusion, diabetes of 4 and 32 weeks duration induced an increase in the tissue content of nNOS in the gastroduodenum of rat. The increase in the level of nNOS in the gastroduodenum of diabetic rats may explain why impaired gastric emptying is common in patients with diabetes.

Effect of malathion on apoptosis of murine L929 fibroblasts: a possible mechanism for toxicity in low dose exposure

While acute organophosphorous compound poisoning due to inhibition of acetylcholinesterase is a well-established clinical entity, the existence of chronic poisoning due to exposure to low levels of organophosphorous compounds (below the threshold required for cholinergic clinical symptoms) is a hotly debated issue. In this study, we have evaluated the effects of noncholinergic doses of malathion (0.01-20 microM) on apoptosis of murine L929 fibroblasts. Employing flow cytometric and caspase activation analyses we demonstrate that malathion induces apoptosis in L929 cells in a dose- and time-dependent manner. The initiator caspases (caspase-8 and caspase-9) as well as the effector caspase (caspase-3) were activated by the treatment of L929 cells with malathion. Exposure of L929 cells to malathion in the presence of a general inhibitor of caspase, z-VAD-FMK abolished the apoptotic effect of the compound. In addition, malathion induced an increase in the expression of the pro-apoptotic protein p53. However, the induction of p53 expression was subsequent to activation of the caspase cascades. The present findings suggest, that the cytotoxicity of malathion at noncholinergic doses is mediated through caspase-dependent apoptosis.

Influence of paraoxon (POX) and parathion (PAT) on apoptosis: a possible mechanism for toxicity in low-dose exposure

The acute effects of poisoning with organophosphorus compounds (OPCs) are well known and have been described extensively. Most of the clinical symptoms are due to inhibition of acetylcholinesterase. Although acute OPC poisoning is a well-established clinical entity, the existence of chronic poisoning due to exposure to low levels of OPC (below the threshold required for cholinergic clinical symptoms) is a hotly debated issue. Recent studies have suggested the involvement of OPCs in apoptotic processes. However, the mechanisms by which they modulate this process are poorly investigated. In the present study we evaluated the toxic effect of different concentrations of paraoxon (POX) and parathion (PAT) in murine EL4 T lymphocytes. We examined cellular responses, including induction of apoptosis, involvement of a caspase cascade, the activity of effector caspase (caspase-3) and the biochemical and morphological changes that are the hallmarks of classical apoptosis. The results of our study indicate that at doses below IC(50) POX is a potent inducer of apoptosis, as opposed to PAT that shows little apoptotic effect.

Laparoscopy versus laparotomy management of tubal pregnancy

OBJECTIVE

To compare laparoscopy versus laparotomy management of tubal pregnancy and the reproductive outcome.

METHODS

A retrospective chart review of 81 patients admitted for management of tubal pregnancy was carried out at Riyadh Armed Forces Hospital from January 1998 until January 2000. The patients were divided according to surgical procedure performed into: Group I (33 patients) laparoscopy and group II (48 patients) laparotomy. We evaluated pre and postoperative serum b-human chorionic gonadotrophin levels, total operating time, total blood loss or blood transfusion or both, duration of hospital stay, recurrence rates of ectopic pregnancy and future fertility outcome for all patients.

RESULTS

No differences were found between both groups in patient age, parity, size of adnexal mass, condition at the time of presentation, site of tubal pregnancy, previous history of ectopic, pre and postoperative serum b-human chorionic gonadotrophin and the total operating time. There were significant reductions of total blood loss, number of blood transfusion units, and duration of hospital stay, in the laparoscopic group compared to the laparotomy group. A total of 54 patients desired pregnancy, 23 patients in the laparoscopy and 31 patients in the laparotomy group. No significant differences were found in the fertility outcome between both groups. The rates of subsequent intrauterine pregnancy were 74% (17/23) in the laparoscopy group and 61%, (19/31) in the laparotomy group and the rates of subsequent ectopic pregnancy were 4% (1/23) in the laparoscopy group and 10% (3/31) in the laparotomy group.

CONCLUSION

Laparoscopic treatment of ectopic pregnancy in hemodynamically stable patients offers major economic benefits superior to laparotomy in terms of less need for blood transfusion, shorter duration of hospital stay and convalescence.

Protective effect of folinic acid on low-dose methotrexate genotoxicity

INTRODUCTION

Methotrexate (MTX) is an antineoplastic agent widely used in low dose to treat patients with rheumatoid arthritis (RA). Its side effects can partly be explained by folate antagonism. Folinic acid (Leucovorin) is generally administered with MTX to decrease MTX-induced toxicity. However information regarding the inhibitory effect of folinic acid against cytogenetic damage caused by MTX is limited. The aim of this study was to assess the protective effect of folinic acid against MTX-genotoxicity.

METHODS

This study was done on Wistar albino rats and in patients with RA. Forty rats of both sexes were randomized into four equal groups and dosed in the following way: Group-I, distilled water vehicle; Group-II, 0.5 mg/kg folinic acid; Group-III, 0.5 mg/kg MTX; Group-IV, 0.5 mg/kg folinic acid plus 0.5 mg/kg MTX. Doses were given i.p., once daily for 8 consecutive days. A bone marrow chromosomal study and a micronucleus test were performed for each rat. Twenty patients with RA (5 males and 15 females) on a 10 mg weekly dose of MTX, i.m., for one month, were administered the same dose of MTX in addition to 10 mg of folinic acid as a single dose 4 hours after MTX administration, i.m., every week for another 4 weeks. Chromosomal studies as well as a micronucleus test were evaluated for each patient.

RESULTS

MTX produced a significant genetic injury as proved by the increased incidence of chromosomal aberration and micronuclei formation in Group-III animals. Inversely, folinic acid (group IV) produced a significant protection against genetic damages induced by MTX. In RA patients, folinic acid provides satisfactory improvement of MTX-induced genetic damage.

CONCLUSION

Folinic acid has a protective affect against MTX genotoxicity in human as well as in animal models.

Mechanism of H(+)-coupled formate transport in rabbit renal microvillus membranes

It has been proposed that a major fraction of Cl- absorption in the mammalian proximal tubule occurs by Cl-/formate exchange across the apical membrane with recycling of formate by nonionic diffusion. The purpose of this study was to characterize the mechanism of formate recycling in rabbit renal microvillus membrane vesicles. Formate uptake was stimulated by an inside-alkaline pH gradient. When external pH (pH alpha) was varied at constant internal pH (pHi), the initial rate of formate uptake was less than predicted for nonionic diffusion of formic acid at constant formic acid permeability. When pHi was varied at constant pHi, the initial rate of formate uptake exhibited cooperative and saturable kinetics with respect to pHi, in contrast to the pHi independence predicted for nonionic diffusion. pH gradient-stimulated [14C]formate uptake was stimulated by internal formate, indicating formate/formate exchange. pH gradient-stimulated formate influx was sensitive to inhibition by 1 mM 4,4'-diisothiocyanostilbene-2, 2'-disulfonic acid but not by furosemide or hydroxycinnamate. We conclude that pH gradient-stimulated formate uptake takes place by a carrier-mediated process of H(+)-formate cotransport, OH-/formate exchange, or facilitated formic acid diffusion, rather than solely by passive nonionic diffusion through the lipid bilayer.

Electrophoretic polymorphism in rabbit tear lysozyme

Rabbit tears were found to contain two lysozymes which differed in their electrophoretic mobility and were designated tear lysozymes 1 and 2. Rabbit tear lysozyme 1 was purified to homogeneity by conventional purification methods. It was found to be distinct from other known mammalian c-type lysozymes, rabbit tear lysozyme 2 and the major rabbit gastrointestinal lysozyme. The activity profile is centered around the neutral region with an optimum of 7 which is slightly lower than that for chicken lysozyme. The thermal stability as well as inhibition profiles by the substrate analogues, N-acetylglucosamine (NAG) and chitotetraose (NAG)4 are comparable to those of chicken lysozyme. Based on its molecular weight and catalytic properties this isozyme is classified as a c-type lysozyme.

Papillary immature metaplasia of the cervix: a distinct subset of exophytic cervical condyloma associated with HPV-6/11 nucleic acids

A subset of exophytic cervical precursor lesions are composed of immature metaplastic cells that differ from conventional condylomata by the virtual absence of koilocytotic atypia and the presence of slender filiform papillae. We evaluated a series of exophytic cervical lesions containing this morphology for HPV nucleic acids and compared the associated HPV types with conventional exophytic condylomata of the cervix. Six of six exophytic condylomata and five of six papillary immature metaplasias (PIM), respectively, contained HPV type 6/11 by in situ hybridization. Subtyping of three PIM by polymerase chain reaction combined with direct sequencing revealed nucleic acid sequences consistent with HPV 6/11. PIM were distinguished from high-grade squamous intraepithelial lesions by the rarity of mitoses and by the uniformity of nuclear size and staining intensity with multiple chromocenters. However, these lesions tended to involve the more cephalad region of the cervical transformation zone, and three cases extended deeply into the endocervix with two requiring conization for a definitive diagnosis. Although their bland morphology and association with HPV 6/11 nucleic acids suggest a benign process, their location within the endocervical canal implies that these variants of condyloma may differ biologically from conventional exophytic condylomas of the cervix. The differential diagnosis of PIM and potential explanations for their distinctive morphology, are discussed.

Coexpression of the human papillomavirus type 16 E4 and L1 open reading frames in early cervical neoplasia

Although the E4 open reading frame (ORF) of human papillomaviruses (HPV) encodes an abundant protein in cutaneous warts, the location and extent of HPV E4 expression in genital precancers, specifically those associated with HPV-16, has not been described. Expression plasmids (pATH) containing segments of the HPV-16 E4 (3401-3620) and L1 (6151-6792) open reading frames (ORFs) were induced and expressed in bacteria and the resulting fusion proteins were used to elicit antisera in rabbits. Antisera reacting to the E4 and L1 components of the fusion proteins were used to screen biopsies from 150 cervical precancers (cervical intraepithelial neoplasia) and condylomata. Six biopsies exhibiting specific immunostaining with the anti-E4 sera. Staining was cytoplasmic, and occurred virtually always in foci containing immunostaining for L1 proteins. Moreover, analysis of these 6 cases and 22 others for HPV-16 RNA by RNA-RNA in situ hybridization demonstrated a similar correlation between E4 immunostaining and the presence of abundant transcripts specific to HPV-16. These data are consistent with the hypothesis that expression of the HPV-16 E4 ORF is dependent upon viral replication and epithelial differentiation, similar to L1 expression, and that the E4 epitopes identified by the rabbit antisera may be unique to HPV-16 relative to other common cervical papillomaviruses.

Kinetic properties of the Na+/H+ antiporter of lymphocytes from the spontaneously hypertensive rat: role of intracellular pH

Enhanced activity of the Na+/H+ antiporter is increasingly reported as a feature of cells from hypertensive subjects but the intracellular pH (ipH) dependency of its activity has not been examined. This study was designed to characterize the kinetic properties of the Na+/H+ antiporter in lymphocytes from adult spontaneously hypertensive rats (SHR) and in those from age-matched normotensive Wistar-Kyoto (WKY) controls. Steady-state ipH, estimated from the measurement of BCECF fluorescence, was significantly lower in lymphocytes from the SHR than in those from WKY rats (7.09 +/- 0.02, n = 17 and 7.17 +/- 0.03, n = 19, respectively, P less than 0.025). The velocity of the antiporter determined from the product of the change in intracellular hydrogen ion concentration (i[H+]) by the buffering power measured concurrently at each starting ipH exhibited similar kinetic parameters in SHR and WKY cells: Vmax, 72 +/- 18 vs. 79 +/- 24 mM H+/30 s; pKH, 10.04 +/- 0.87 vs. 8.49 +/- 0.80; and Hill coefficient, 1.67 +/- 0.12 vs. 1.44 +/- 0.10, respectively. Likewise, no significant differences were observed between SHR and WKY cells in either the Km (29 +/- 5 and 32 +/- 8 mM, respectively) or the Vmax (6.0 +/- 1.0 and 5.53 +/- 1.0 mM H+/30 s, respectively) of the sodium activation curve. We conclude that while the ipH of SHR lymphocytes is reduced, the kinetic properties of the Na+/H+ antiporter are virtually identical in SHR and WKY lymphocytes. Consequently, a primary abnormality in the activity of this antiporter is not an inherent feature of lymphocytes from the SHR model of genetic hypertension. We propose that the activity of the Na+/H+ antiporter in SHR cells is apt to be increased as a result of reduction in ipH which dictates a higher set point in its steady-state activity.

Effects of hydrotropic agents on the solubility, precipitation, and protein binding of etoposide

Etoposide, a commonly used anticancer agent, has an aqueous solubility of 0.2 mg/mL. It is formulated for intravenous use as a more concentrated solution (Vepesid; 20 mg/mL) with polysorbate 80 and with cosolvents. In this work, hydrotropic agents such as sodium benzoate, sodium o-hydroxybenzoate (sodium salicylate), sodium 2,5-dihydroxybenzoate (sodium gentisate), and the sodium salts of 2,4-dihydroxy- and 2,6-dihydroxybenzoic acid and of 2,4,6-trihydroxybenzoic acid have been used as alternative solubilizers of etoposide. The weakest and strongest interactants with etoposide were, respectively, sodium benzoate and sodium 2,4,6-trihydroxybenzoate. The effect of mono- and dihydroxybenzoates on etoposide solubility was intermediate. Although sodium 2,4,6-trihydroxybenzoate is the most efficient solubilizer, its use is limited by its own low aqueous solubility. The effect of sodium salicylate and other formulation ingredients on the in vitro protein binding and precipitation of etoposide upon dilution with normal saline and human plasma has been studied. Etoposide binds to the extent of 94% to human serum albumin (HSA) and human plasma, but only 24% to bovine serum albumin (BSA) in vitro. Sodium salicylate significantly decreased the binding of the drug to both HSA and human plasma, whereas the components of Vepesid did not. Dilution of Vepesid (1:2 and 1:3) with plasma in vitro resulted in immediate precipitation, while the corresponding dilutions of etoposide aqueous solution (20 mg/mL in 2 M sodium salicylate) produced no precipitate for the first hour.

The effect of hydrotropic agents on the heat coagulation of bovine serum albumin

The effect of two hydrotrophic solubilizers on the heat coagulation of bovine serum albumin (BSA) has been investigated. Photon correlation spectroscopy indicated possible unfolding of BSA molecules in solutions of sodium benzoate and sodium salicylate at 25 degrees C. The effect of these hydrotropes on the heat coagulation of BSA was concentration-dependent. Relatively low concentrations stabilized the protein structure as indicated by the increase in the transition temperature(Tm) and induced gelation at temperatures and BSA concentrations lower than those required in the absence of hydrotropes. Higher concentrations of the hydrotropes considerably reduced Tm and inhibited gelation of BSA, the effect of sodium salicylate being more pronounced, as was the lower aggregation rate of BSA. The behaviour of these hydrotropes as protein denaturants differs from that of neutral electrolytes but is similar to that of concentrated solutions of urea.

Solubilization of water by hydrotropic salts

The effect of some electrolytes, nonelectrolytes, surfactants, and hydrotropic salts on the solubility of water in 1-butanol and 1-hexanol was investigated. While sodium chloride and sodium acetate decrease the solubility of water in 1-butanol, urea has no significant effect. The ionic surfactants, sodium lauryl sulfate and cetrimide, cause an initial decrease in the solubility of water in 1-butanol followed by an increase at high surfactant concentrations. The nonionic surfactant, polysorbate 20, does not show the initial decrease in water solubility. On the other hand, the hydrotropic salts, sodium benzoate, sodium salicylate, and sodium gentisate, are shown to be the best water solubilizers in 1-butanol. Sodium salicylate showed the maximum solubilizing power. The effect of sodium benzoate, sodium salicylate, and sodium lauryl sulfate on the solubility of water in 1-hexanol was also investigated. Similar results were obtained.

The nutritional quality of drum-dried algae produced in open door mass culture

The yield of three large scale cultures of Scenedesmus acutus, Chlorella vulgaris, and Coelastrum proboscideum was drum dried. The amino acid composition of the three species proved to compare well with the FAO (11) amino acid pattern except for methionine and isoleucine. Bio-assay evaluation of the three algal proteins gave the following values: protein efficiency ratio, 1.9-2.1; net protein ratio, 2,4-2.8; biological value, 75-78; digestibility coefficient 88-89; and calculated net protein utilization 67-69. Total nucleic acid content was about 4%. Uric acid content in the plasma of rats fed Scenedesmus, Chlorella, and Coelastrum diets was significantly higher (P less than 0.05) than in plasma of rats fed on a casein diet.

Effects of phenobarbitone and phenytoin on folate catabolism in the rat

The effects of phenobarbitone and phenytoin on the catabolism of oral [2-14C] and [3',5',7,9-3H] folic acid were investigated. Normal rats were found to excrete an excess of 3H-labelled compounds into the urine and 14C-labelled compounds into the faeces. Phenytoin abolished this urinary 3H imbalance and also delayed and prolonged the overall excretion of radioactive material. Phenobarbitone appeared to increase the amounts of urinary scission products in the first 24 hr but over the 0-72 hr period both anticonvulsants decreased folate polyglutamate catabolism. As the anticonvulsants used in these experiments decreased folate catabolism in the rat it is unlikely that the megaloblastic anaemia caused by chronic anticonvulsant therapy is due to induction of the enzymes responsible for folate breakdown in vivo.

Folate metabolism in man: the effect of malignant disease

The metabolism of [2-14C]+[3', 5', 7, 9-3H] folic acid and [214C]+[3', 5', 7, 9-3H] 10-formylfolate was studied in hospital inpatients. Metabolites detected in the urine after folic acid feeding included the unchanged compound, other folates and a number of breakdown products, such as p-acetamidobenzoyl-L-glutamate and p-acetamidobenzoate. This confirms the existence of a folate catabolic pathway in man. Patients with malignant disease excreted less of the dose in urine, incorporated more into the reduced folate pool, and showed decreased catabolism of folate, when compared to controls. 10-Formylfolate was excreted largely unchanged, and appears not to be reduced by man. Also 10-formylfolate interfered with the reduction of folic acid given simultaneously.

Folate catabolism in tumour-bearing rats and rats treated with methotrexate

The metabolism of (2-14C) + (3',5',7,9-3H) folic acid was studied in normal rats, tumour-bearing rats and rats treated with methotrexate (MTX). The experiments were designed to investigate changes in the catabolism and folate. The breakdown of folate to scission products was again demonstrated to be a normal phenomenon. Catabolites excreted included p-acetamidobenzoate, p-acetamidobenzoyl-L-glutamate, 3H2O, urea and a number of pterins. The catabolic process was decreased in the presence of a tumour and increased by the administration of MTX. MTX also led to the excretion of 4 additional radioactive pterins not found in normal urine. The possible mechanisms of folate breakdown are discussed with reference to the point of action of MTX.

Topically applied griseofulvin in the treatment of superficial dermatomycoses in Egypt

One-hundred and fifty-five patients suffering from T. Capitis, T. Corporis, T. Cruris and T. Verisicolor participated in studies of topically applied griseofulvin. Various concentrations of the drug were prepared in an ointment form in a new solvent system. Successful results were obtained with the 2% preparation in cases of T. Corporis, T. Cruris and T. Versicolor. Failure of the therapy was observed in cases of T. Capitis. No side-effects occurred in any patient using the 2% preparation. In the opinion of the authors, topically applied griseofulvin in the new solvent system is safe and highly effective in the treatment of superficial dermatomycoses.

Comparative study of the gastrocnemius and soleus muscles of the Egyptian desert rodent Gerbillus pyramidum and the albino rat

The hind limb muscles of the Egyptian desert rodent Gerbillus pyramidum and the albino rat were studied macroscopically and microscopically, using ordinary and histochemical techniques. The results revealed a relatively long hind limb and a relatively long tendon of the gastrocnemius group in G. pyramidum as compared with the albino rat. The dark fibres (red) were dominant in the muscles of the former animal and its spindles similarly contained more dense intrafusal fibres than the spindles of the albino rat. The correlation between these findings and the frequency and power of movement of the hind limbs in G. pyramidum was discussed.