Production, purification, and characterization of chandramycin, a polypeptide antibiotic from Streptomyces lydicus

A plant pathogenic actinomycete identified as Streptomyces lydicus was isolated from the deep-pitted scab lesions of potato tubers. This strain produces a new polypeptide antibiotic named chandramycin. The antibiotic was isolated from culture broth by extraction with organic solvents and purified by chromatography. The purified antibiotic is a light-yellow crystalline compound soluble in water and in most organic solvents. Amino acid analysis of the acid hydrolysates of chandramycin revealed the presence of glycine, cis-methyl proline, valine, beta, beta-dimethylaminobutyric acid, beta-methyl-phenylalanine, and beta-2-thioazolyl-beta-alanine. The amino acid composition of chandramycin is qualitatively similar to that of a known antibiotic, bottromycin A2. Chandramycin showed activity against several gram-positive and a few gram-negative species of bacteria. It showed a strong activity against anaerobic microorganisms. Oral doses of antibiotic when administered up to 466 mg/kg of body weight failed to produce any observable toxic effect in mice.

Passive transfer of arthritis to mice by injection of human anti-type II collagen antibody

The serum IgG fraction from a patient with seronegative rheumatoid-like arthritis which contained a high anti-type II collagen antibody titer was injected intravenously into mice susceptible to type II collagen-induced arthritis. A mild, transient, inflammatory arthritis was observed in 20 to 25% of the animals, whereas histologic signs of disease were evident in most of the injected mice. Purified human anti-type II collagen immunoglobulin injected into the knee joints of mice was also shown to induce a transient, inflammatory arthritis. Radiolabeled human anti-type II collagen IgG was shown to accumulate in the peripheral joints of mice, and the specificity of the antibody was shown to be similar to the specificity of anticollagen antibody eluted from the joints of mice with collagen-induced arthritis.

Effects of ethanol ingestion on maternal and fetal glucose homeostasis

Carbohydrate metabolism has been studied in the offspring of rats fed liquid diet containing ethanol during gestation (EF group). Weight-matched control dams were given liquid diet either by the pair-fed technique (PF group) or ad libitum (AF group). EF and PF dams showed reduced food consumption and attenuated gain in body weight during the gestation period compared with the AF group. Blood glucose, liver glycogen, and plasma insulin levels were significantly reduced in EF and PF dams. Ethanol ingestion resulted in a significant decrease in litter survival and fetal body weight. At term, EF pups on average showed a 30% decrease in blood glucose levels and 40% decrease in plasma insulin levels compared with AF pups. One hour after birth, EF pups exhibited a marked increase in blood sugar level compared with either control group; subsequently, there was a marked decrease in blood glucose levels in EF pups. Liver glycogen stores were significantly reduced in term EF fetuses and were mobilized more rapidly in EF neonates than in either control group. Fetal hyperinsulinemia disappeared shortly after delivery in control pups, as expected; however, in EF pups, the fall in plasma insulin level was gradual. Fetal and neonatal plasma glucagon levels were not altered by ethanol exposure in utero. Blood glucose levels remained significantly low at 2 days of age in EF pups, but reached near control values at 4 days of age. Plasma insulin and glucagon were nearly equal in EF and control pups at 2 and 4 days of age. These results show aberrations in blood glucose, plasma insulin, and liver glycogen levels in offspring exposed to ethanol in utero.

Comparison of regimens of treatment with sodium stibogluconate in kala-azar

One hundred and twenty six patients with kala-azar (visceral leishmaniasis) were allocated at random to one of two groups for treatment with sodium stibogluconate. One group was treated for 20 days; in the other group the patients were assessed after 20 days' treatment and treatment was continued if necessary. Both groups were followed up for six months. There was no significant difference in symptomatic outcome between the two groups at 20 days. At six months eight of the patients in the group treated for 20 days had relapsed and 54 were cured. Of the group given more than 20 days' treatment if necessary, 62 were cured and none had relapsed (12 required more than 20 days' treatment). This difference between the two groups was significant. One patient in each group did not respond to sodium stibogluconate, but both were were cured with pentamidine. Altogether 104 patients were cured after 20 days' treatment; 20, including the eight who relapsed, were cured after more than 20 days' treatment. There was no significant difference between the two groups in the side effects of the drug, which were minor. The longer courses of treatment (50 days in one patient) were well tolerated. It is suggested that the traditional six day course of treatment with sodium stibogluconate for kala-azar is grossly inadequate and that a longer course is required to prevent relapse.

Effect of clomiphene citrate on the testis, epididymis and accessory sex glands of the musk shrew (Suncus murinus L.)

The effects of oral administration of clomiphene citrate (50 mg/kg body weight) on the testis, epididymis and accessory sex glands of the musk shrew were investigated. The drug induced duration-dependent alterations in the weight and histology of these organs. The drug produced significant reduction in testicular weight with severe degenerative changes in seminiferous tubules; Leydig cells were also atrophied. However, no significant change was found in the levels of protein, RNA and DNA in the testes of drug-treated animals as compared with controls. Epididymis in drug-treated shrews exhibited significant decrease in weight and regressive histological changes. Spermatozoa collected from the cauda epididymidis of drug-treated shrews were immotile and often fragmented. Clomiphene treatment also induced regressive histological changes in the prostate and ampullary gland accompanied by significant decrease in the weight. The treatment also caused significant decrease in the level of fructose in the ampullary glands. Following withdrawal of the drug, the reproductive organs returned to their normal state. Full recovery was noticed in the accessory sex glands 28 days after drug withdrawal. However, full spermatogenic activity and normal epididymal histology were achieved only after 56 days The mechanism of action of clomiphene on the male reproductive organs is briefly discussed.

Effect of thyrotoxicosis on ethanol metabolism and on hepatic ethanol oxidation enzymes

The influence and mechanism of action of T4 treatment on ethanol metabolism was investigated by the determination of ethanol elimination in intact rats and by the estimation of alcohol dehydrogenase and the microsomal ethanol oxidizing system activity in isolated rat liver. The rate of ethanol degradation was significantly decreased to 65% of control values in T4-treated rat liver. Similarly blood ethanol disappearance rate was significantly inhibited in thyrotoxic rats as compared to euthyroid animals. Hepatic alcohol dehydrogenase activity was reduced to 39% of control values as a result of T4 treatment; however, the microsomal ethanol oxidizing system activity was not affected. These data suggest that reduction in blood ethanol disappearance rate is associated with inhibition of hepatic alcohol dehydrogenase activity in thyrotoxicosis.

Serological and biochemical characterization of class II antigens in B10.W lines

Class II molecules of 17 B10.W lines (i.e., congenic lines carrying H-2 haplotypes of wild mice on C57BL/10Sn or B10 strain background) were analyzed by immunochemical methods of precipitation and co-precipitation. The analysis included typing for previously defined antigenic determinants, as well as determinants defined by new reagents, and mapping of the genes controlling these determinants. Using this approach, an Ia chart of the typed B10.W lines could be constructed. Genes controlling determinants Ia.38, 102, 103, 104, 105, and 106 were mapped into A (A beta or A alpha) locus; genes controlling determinants Ia.41. 107. 108, and 109 were mapped in the E (E beta or E alpha) locus. The study suggests that the polymorphism of at least some of the class II loci could be as high as that of the class I loci.

An H-2 haplotype possibly derived by crossing-over between (A alpha A beta) duplex and the E beta locus

The B10.STA62 strain carries the H-2w27 haplotype derived from a wild mouse captured in the vicinity of Ann Arbor, Michigan. Products of two class II loci composing this haplotype, A alpha and A beta, are serologically, biochemically (by tryptic peptide mapping), and functionally indistinguishable from products controlled by the Ab alpha and Ab beta genes of the B10.A(5R) strain. In contrast, the polypeptide chain controlled by the third class II locus, E beta, is different from that controlled by the Eb beta gene. This Ew27 beta chain lacks an antigenic determinant present on the Eb molecule and carries determinants lacking on the Eb molecule, the Eb beta and Ew27 beta peptide maps differ in at least six peptides, and cytotoxic T cells specific for the Eb beta chains do not react with B10.STA62 target cells. This great difference between the Eb beta and Ew27 beta chains suggests that the corresponding genes have not been derived from one another by a direct mutational conversion; instead, H-2w27 appears to be a recombinant haplotype derived by crossing-over between the A alpha A beta duplex and the E beta locus. This is the first recombinant discovered separating these class II loci.

Effect of vasectomy on the testis and accessory sex glands of the musk shrew, Suncus murinus L

The effects of uni- and bilateral vasectomy on the testis and accessory sex glands were studied at intervals up to six months. Vasectomy induced degenerative changes in the seminiferous tubules during the first four months after the operation; thereafter a partial recovery of spermatogenesis was noticed at six months post-vasectomy. Unilateral vasectomy induced degenerative changes only in the ipsilateral testis; the contralateral testis presented normal histology and showed no evidence of compensatory hypertrophy. The Leydig cells, however, remained unaffected in vasectomized shrews. No significant change was found in the concentrations of protein, RNA and DNA in the testis and of fructose in the ampullary gland in uni- and bilaterally vasectomized animals as compared with controls. The absence of any change in the concentration of fructose, weight of the accessory sex glands and histology of the ampullary gland and Leydig cells in vasectomized animals suggests that endocrine functions of the testes are not affected by vasectomy.

The histocompatibility-2 system in wild mice. XI. Ss and Slp properties of wild-derived H-2 haplotypes

In this study, 14 B10.W lines were examined for genetic traits associated with the Ss protein and Slp alloantigen. Three B10.W lines were found to possess low levels of serum Slp alloantigen. Of these three Slp-positive lines, expression of the alloantigen was sex-limited in two lines (B10.LIB55 and B10.STA12) and constitutive, i.e., found in both sexes, in the remaining line (B10.KPB128). Lines which were found to be Slp-negative were also tested for IA-controlled immune response to Slp alloimmunization. The finding that one of these Slp-negative lines produced no detectable anti-Slp indicates that nonresponder alleles exist in wild populations. Further, the discovery of an unexpected immune response to Slp in F1 hybrids involving lines B10.LIB55 and B10.STA12 suggests the existence of a variant form of Slp alloantigen in these lines.

The Oaxaca, Mexico, Earthquake of 29 November 1978: A Preliminary Report on Aftershocks

Aftershocks of the 29 November 1978 Oaxaca, Mexico, earthquake (surface-wave magnitude Ms = 7.8) define a rupture area of about 6000 square kilometers along the boundary of the Cocos sea-plate subduction. This area had not ruptured in a large (Ms >/= 7), shallow earthquake since the years 1928 and 1931 and had been designated a seismic "gap." The region has also been seismically quiet for small to moderate (M >/= 4), shallow (depth </= 60 kilometers) earthquakes since 1966; this quiet zone became about six times larger in 1973. A major earthquake (Ms = 7.5 +/- 0.25) was forecast at this location on the basis of the quiescence that began in 1973. The aftershock data indicate that an area approximately equivalent in size to the seismic gap has now broken.

Sterilization of a non-scrotal mammal (Suncus murinus L.) by intratesticular injection of cadmium chloride

The testis of the musk shrew is resistant to subcutaneous administration of cadmium chloride. In contrast, a single intratesticular injection of cadmium chloride (0.01 to 0.03 mM/kg body weight) caused total destruction of germinal epithelium; Leydig cells, however, regenerated after an initial phase of atrophy. Unilateal injection of the drug induced degenerative changes in the injected testis only; the contralateral testis appeared normal macroscopically and histologically. The factors responsible for the differential response of the testes of this non-scrotal mammal to the two routes of administration of cadmium chloride are discussed.

Facial nerve schwannoma

The present article gives a brief and complete account of the incidence, pathology, clinical features, diagnosis, management and prognosis of the schwannoma with special reference to facial nerve schwannomas. A case report of a rare schwannoma of the vertical part of the facial nerve found on biopsy of tissue during a postaural modified radical mastoidectomy is included.

Phacoemulsification versus small incision cataract surgery (SICS): which one is a better surgical option for immature cataract in developing countries?

Background: Several studies have shown comparable visual outcomes of SICS and phacoemulsification (Gogate et al 2007, Ruit et al 2007). Objective: To compare the safety and efficacy of different types of surgical procedures (phacoemulsification versus SICS) for cataract surgery in immature cataract. Material and methods: A prospective randomized controlled trial was carried out involving 93 and 89 patients with immature senile cataract selected for phacoemulsification and SICS respectively. Statistics: Mean values with standard deviations were calculated. P value of less than 0.05 was considered significant. Results: There was no difference between the groups in terms of gender, age and pre-operative visual acuity (p = 0.09). In phacoemulsification group (n=93) more than two thirds and in SICS group (n=89) more than three quarters of the patients had good visual outcome (6/6-6/18) on first postoperative day (p=0.065). Poor outcome (<6/60) was recorded in 6% (phacoemulsification group) and 1% (small incision cataract surgery group). Mean visual acuity was 0.43 ± 0.27 in phacoemulsification group and 0.47 ± 0.24 in SICS group. Mean surgery time was significantly shorter in SICS group (p=0.0003). Statistics: Data were computed and analyzed using the SPSS software program vs 10. The p value of < 0.05 was considered significant. Conclusion: There was no significant difference in visual outcome on first post operative day in between phacoemulsification and SICS technique. However, performing SICS was significantly faster. Small incision cataract surgery with implantation of rigid PMMA lens is a suitable surgical technique to treat immature cataract in developing countries. Keywords: phacoemulsification; small incision cataract surgery (SICS) DOI: 10.3126/nepjoph.v1i2.3682 Nep J Oph 2009;1(2):95-100

Kala Azar- A Diagnostic Dilemma - A Case Report

Kala Azar- A Diagnostic Dilemma - A Case Report