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Sharp narrow nanopetal-like and wrinkled nanoball-like cubic Cu 0.4 Zn 0.6 Fe 2 O 4 -implanted orthorhombic Bi 2 S 3 -capped anatase TiO 2 heterostructures have been synthesized by a two-step hydrothermal process in acidic and basic environments. They have been characterized by high-resolution scanning and transmission electron microscopies, energy-dispersive X-ray spectroscopy, selected area electron and powder X-ray diffractometries, vibrating sample magnetometry, UV-visible diffuse reflectance and photoluminescence spectroscopies, and nitrogen adsorption-desorption analysis. Both the nanostructured composites are superparamagnetic. While the nanocomposite synthesized in acidic environment absorbs in the entire visible and UV spectral regions, the absorption edge of nanocomposite obtained in basic environment narrowly misses the red end of the visible spectrum. The emission spectra of both the nanomaterials are strikingly similar, indicating similar crystal defects in anatase TiO 2 lattice of both the nanocomposites. Although both the nanocomposites degrade dye under visible light, the photocatalytic activity of the sample obtained in acidic environment is superior to that prepared in basic condition. The enhanced photocatalytic activity of the nanocomposite synthesized in acidic environment is rationalized in terms of nanostructure, surface area, and optical properties., Competing Interests: The authors declare no competing financial interest.

Effect of short term (7 days) exposure to safe concentration of HgCl2 (0.5 ppm) and changes 7 days after withdrawl of the treatment on his ophysiologyof ovary and liver in yearlings of Cyprinus carpio were assessed during active phase of reproductive cycle. Noticeable degenerative histophysiological changes were observed in both ovary and liver after exposure which were more prominent in the group with abnormal behaviour. After withdrawl of the HgCl2 treatment the recovery was apparent in both organs but was more appreciable in liver. These observations indicated that even safe concentration of HgCl2 might not be fully devoid of deleterious influence on reproductive functions in Cyprinus carpio.

Ovarian development in Labeo dyocheilus was assessed during active reproductive phase under ambient environmental conditions in captivity and wild. Increasing day length and water temperature seemed favourable for ovarian development in female L. dyocheilus under both conditions. Gonadosomatic index (GSI) was lower in May and higher in July in captivity (6.168 and 13.366) and wild (5.798 and 16.166) respectively Ovarian development started little bit in advance in captivity with late yolk vesicle stage oocyte in May when yolk globule stage oocytes were prominent in wild. Fully grown oocytes with germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) stages were observed in July in both conditions. Degree of transformation of developing oogonials into advance stage oocytes was observed to be better in wild fish compared to captivity reared ones. The histophysiological changes in liver corresponded well to the progression of ovarian development. Successive granulation and vacuolization of hepatocyte cytoplasm were indicative of augmented synthetic activity and probably mobilization of energy content for oocyte growth. These observations indicated that normal ovarian development of L. dyocheilus under captivity in Tarai region of Uttarakhand would be useful for success of its seed production in captivity for stock augmentation in wild or species diversification in aquaculture.

Seasonal ovarian cycle, based on histophysiological changes, and correlative variations in liver were studied in an Indian major carp, Labeo rohita reared in captivity under ambient environmental conditions in Tarai region of Uttaranchal. The oocyte features used for marking ovarian cycle included nuclear-ooplasmic ratio, yolk vesicle incorporation into ooplasm, number and size of nucleolus and differentiation of follicular layer. Based on these features the ovarian cycle in L. rohita was divided into five phases i.e. resting, preparatory, pre-spawning, spawning and post-spawning/regression. The resting and preparatory phases were characterized by the dominating presence of chromatin-nucleolar and yolk-vesicle stage oocytes. The pre-spawning phase ovary was marked by the prevalence of yolk globule stage oocytes having cortical alveoli and differentiating follicular wall. The oocytes containing densely packed yolk-granules and large masses of yolk vesicles and also exhibiting germinal vesicle movement (GVM) signified the ovary of spawning phase. The ovary in regression phase contained pre-ovulatory atretic oocytes and significant number of oogonia. The histophysiological changes in liver showing augmented biosynthetic activity during preparatory and pre-spawning phases seemed well correlated with the gonadal development. The increasing water temperature and day-length apparently was favourable for the gonadal development in L. rohita.

The static bioassay experiments were conducted to study the hematological and behavioural responses of Cyprinus carpio after exposure to mercuric chloride. Three different concentrations i.e. 0.5, 1.0 and 1.5 ppm of mercuric chloride (HgCl2) were used for 8, 16, 24, 48, 72, 96 and 124 hrs for evaluating behavioural responses. Hematological responses were assessed after 60 days exposure to 0.1 ppm of HgCl2. The changes in body colour, movement, sluggishness or activeness, disbalance etc. constituted the observations on behavioural responses. Hematological parameters included total erythrocyte (TEC) and leukocyte (TLC) counts and hemoglobin (Hb) levels. Body colour had changed in all groups after 48 hours. The fish exposed to 0.5 ppm HgCl2 did not show any abnormal activity except colour change throughout the experiment. Though no sign of distress was observed initially in groups exposed to 1.0 and 1.5 ppm HgCl2 but abnormal posturing, disbalance and sluggishness became apparent after 72 hrs and all specimens of 1.5 ppm group had died within 124 hours. TEC and Hb levels decreased whereas TLC increased in both male and female specimens of C. carpio after exposure to 0.1 ppm HgCl2 for 60 days. These observations indicated that mercurial toxicity even at low levels, caused adverse effects on body colour, behavioural responses and hematological parameters like TEC, TLC and hemoglobin levels in C. carpio.

The present study embodies the observations on duration (45, 75 and 105 days) dependent effects of toxicologically low concentration (16 ppm) of a carbamate pesticide, carbofuran, on first ovarian maturity with correlative recovery response by withdrawal of treatment for 30 days in virgin yearlings of common carp, Cyprinus carpio var. Communis. In control fish histological organization of ovary and changes in gonado-somatic index (GSI) revealed the initiation of oocyte differentiation and development at the commencement of experiment in December-January and peak of maturation with fully grown yolky oocytes was attained by the time of termination of experiment in the end of March. In carbofuran exposed groups ovaries exhibited retardation of development and growth evident by significantly decreased GSI and predominace of immature oocytes passing through nuclear-cytoplasmic degeneration of variable magnitude. Severity of degenerative changes was more pronounced with prolonged duration. In recovery group ovaries had experienced regeneration as clued by the presence of oocytes of differential stages including vitellogenic and fully grown oocytes. In liver histopathological changes coupled with significant decrease in hepato-somatic index (HSI) attributed hepatic inactivation in all exposure groups whereas in recovery group an increase in HSI value with marked sign of hepatic reactivation was evidenced. No significant change in values of condition (CF) and somatic condition (SCF) factors substantiated the over all normal health of fish. Lipid and water content of ovary, liver and muscle registered the significant decrease at 105th day of exposure with concomitant augmented value for recovery group. These observations suggest that the commercial formulation of carbofuran, even at this toxicologically low concentration, is equally capable of affecting the first ovarian maturity with associated physiological implications but with reversibility in toxicity by withdrawal of pesticide exposure attributing regeneration in affected organs in due course time.

The effect of chronic exposure to carbofuran (4.5 ppm in static water) for six months on the gonadal histophysiology and hypothalamo-neurohypophyseal complex was studied in Channa punctatus. Experimental observations revealed significant inhibition of gonadal development with associated degenerative abnormalities as evidenced by ovarian and testicular histology and reduced gonadosomatic index. Degenerative changes in ovary were exihibited by stage I (oogonium) and stage II (immature/non-vitellogenic) oocytes as marked by perinuclear ooplasmic lysis, clumping and dissolution resulting in disintigration of nuclear material altogether attributed to complete degeneration of such oocytes. Testicular deleterious changes included degeneration of spermatogenic elements and necrosis of interstitial cells of Leydig. Correlative histophysiological changes were also observed in the pituitary gonadotrophs and hypothalamic, nucleus pre-opticus, neurons that were smaller, inactive and less in number with associated necrosis. Corresponding to the changes in nucleus pre-opticus neurons, significant inhibition of brain monoamine oxidase enzyme activity was also recorded in treated group. These observations suggest that carbofuran even at low concentration level under long-term exposure is capable of inducing retardation of gonadal development which might have been mediated through the impairment of the hypothalamo-neurohypophyseal-gonadal axis in this species.

Objectives: To assess the efficacy and tolerability of aminosidine compared with sodium stibogluconate for treating visceral leishmaniasis., Design: Randomised, unblinded, controlled trial with 180 day follow up., Setting: Kala-Azar Research Centre, Brahmpura, Muzaffarpur, Bihar, India., Subjects: People of either sex aged 6-50 years with symptoms and signs suggestive of visceral leishmaniasis (fever, loss of appetite, enlarged spleen) with leishmania amastigotes detected in Giemsa stained aspirates of spleen or bone marrow., Interventions: Aminosidine at three daily doses (12, 16, and 20 mg/kg) for 21 days and sodium stibogluconate 20 mg/kg/day for 30 days., Main Outcome Measures: Laboratory measures of efficacy: parasite count, haemoglobin concentration, white cell count, platelet count, serum albumin concentration. Clinical measures of efficacy: spleen size, fever, body weight, and liver size. Measures of safety: liver and renal function tests, reports of adverse events., Results: Of the 120 patients enrolled (30 per treatment arm), 119 completed treatment and follow up. Cure at end of follow up was achieved in 23 (77%), 28 (93%), and 29 (97%) patients treated with 12, 16, and 20 mg aminosidine/kg/day respectively, and in 19 (63%) patients given sodium stibogluconate. At 16 and 20 mg/kg/day, aminosidine was significantly more active than sodium stibogluconate in both clinical and laboratory measures of efficacy. No significant clinical or laboratory toxicity occurred in any treatment group., Conclusions: A 21 day course of aminosidine 16 or 20 mg/kg/day should be considered as first line treatment for visceral leishmaniasis in Bihar.

In a prospective study, 80 cases of fever with hepatosplenomegaly, anemia and leucopaenia coming from the hyperendemic zones for visceral leishmaniasis of North-Bihar, India were screened and subjected to bone marrow or splenic puncture for demonstration of Leishman-donovan bodies (LDB) and DIRECT AGGLUTINATION TEST (DAT) with antigen prepared by Harith et al. 59 cases were confirmed for Visceral Leishmaniasis (VL) by demonstration of LDB in which DAT was also positive in different titres ranging from 1:1600 onwards. Out of 21 cases in which the bone marrow was negative for parasite, DAT was positive in 10 cases. 8 Out of 10 cases responded to WHO regimen of treatment with sodium stibogluconate (SSG). Remaining two cases who did not respond to this therapy became positive for parasites on subsequent splenic aspirate. They were treated with pentamidine isethionate and were cured. 11 out of 80 cases showing a titre of 1:400 or lower in DAT, 6 proved to be cases of enteric fever and 5 of malaria. Thus DAT using Harith's antigen was found to be 100% sensitive and specific in detection of early cases of Indian VL.

128 untreated cases of Kala-azar were divided in 4 equal groups of 32, Group A was treated with Sodium Stibogluconate (SSG) in the dose of 20 mg/kg/body wt. for 30 days. Group B was treated SSG plus allopurinol in the dose of 20 mg/kg/body wt. orally in divided dosage for 30 days. Group C received SSG plus Ketoconazole 600 mg orally in divided dosage for 30 days. Group D in addition to SSG also received levamisole in single oral daily dose of 13 mg/kg/body wt. for 30 days. Response of Group B, C and D was compared to Group A. Results from this study revealed combination of allopurinol with SSG to be statistically not superior to SSG alone.

This study performed by intraneuronal tracing directly demonstrates the presence of sympathetic postganglionic fibers in the cranial vault of the rat. Superior cervical sympathetic ganglia were injected with horseradish peroxidase (HRP), and after a 48-hour period, to permit anterograde axonal transport, the animals were sacrificed after in situ perfusion. An area of the calvaria that included portions of the frontal and parietal bones was fixed, decalcified and sectioned. HRP-containing axons were localized in the developing frontal and parietal bones of the calvaria. Adrenergic innervation was not demonstrated in sutural tissue (superior sagittal, coronal or metopic) by this technique. To our knowledge, this study is the first to trace sympathetic nerve fibers in the rat calvaria by intra-axonal transport of HRP.

In vivo effects of fibroblast growth factor (FGF) on osteogenesis were evaluated in the chick embryo. Autoradiographic studies of 3H-proline labeling over bone matrix indicated that 24 h after treatment on day 11, FGF stimulated osteogenic cell proliferation, while inhibiting the production of bone matrix collagen. However, 4 days after multiple doses of FGF, the large pool of newly formed osteogenic and chondrogenic cells expressed their function with the increased formation of matrix. The data provide in vivo evidence of the effects of exogenous FGF on osteogenesis and also point to a possible role for FGF both in embryonic osteogenesis and in fracture repair.

Fifteen patients, men and women aged 18 to 65 years, were treated for periodontitis. Each patient had at least two bilateral intrabony defects; one was designated the experimental site and the other the control site. Both sites were surgically debrided, but one osseous defect received an HTR polymer implant. Patients were followed for 12 months postoperatively. Maximum pocket reduction occurred within 2 months of initial therapy in both experimental and control sites. Initially, pocket reduction was significantly greater in implanted sites than in control sites, but this difference did not occur subsequently. At the end of the 12 months, pocket reduction responses were similar at control and implanted sites.

In vivo effects of FGF on osteogenesis in the chick embryo were evaluated. Day-11 embryos were injected with FGF followed by radiotracers. 3H-thymidine labelling of osteogenic cells was significantly higher following FGF administration; 3H-proline labelling over bone matrix was greater in the controls. Cartilage cells and matrix were sparsely labelled indicating a low level of metabolic activity. These data provide the first in vivo evidence that FGF stimulates osteogenic cell proliferation, while inhibiting production of bone matrix collagen. A role for FGF in embryonic osteogenesis and in fracture repair is suggested.

This study demonstrates, via immunohistochemistry and bioassay, the presence of NGF in embryonic bone and cartilage of the chick. Embryos were killed on days 6-9 of incubation at 12 h intervals, and on days 10-18 at 24 h intervals. Paraffin-embedded sections of hind limbs or buds were immunostained with a polyclonal antibody against NGF and the biotin-avidin-horseradish peroxidase technique. Immunostaining was positive in both bone and cartilage, with cartilage staining more intensely. For bioassay, bones from the hind limbs of 9- and 12-day embryos were fast-frozen, lyophilized, and homogenized with Medium 199 (M199). Dorsal root ganglia from 8-day embryos were cultured for 24-36 h with rooster plasma, M199, and varying concentrations of bone homogenate. Significant neurite outgrowth was seen, with the greatest response elicited by 12-day bone homogenate. Addition of anti-NGF to the cultures abolished neurite outgrowth. The results indicate that NGF is present in cartilage and bone of the chick embryo; it may determine the density of sympathetic innervation to the developing skeletal tissues.

Earlier studies have shown that one week after sympathectomy in the rat, both bone apposition and resorption are significantly altered. Resorption in the incisor socket was now examined 1, 3 and 5 days after surgical sympathectomy. Morphometric analyses indicated that the total resorbing surface, active resorbing surface and number of osteoclasts per socket were increased one day after sympathectomy; the area and length of the bone surface of the socket were not significantly altered. Sympathetic denervation thus affects bone resorption within the first few hours after surgery.

Visual examination of the intensity of Procion dye in hamster femurs revealed that dye incorporation decreased during hibernation. Little or no dye was observed after hibernation lasting longer than 50 days. It seems that hibernation may be associated with increased bone resorption and a loss of bone matrix.

Guanethidine sulfate was administered to rats from birth to 14 days of age. Cell counts were carried out in the superior cervical sympathetic ganglion at 30, 45, and 90 days of age. Massive permanent destruction of sympathetic ganglionic cells was demonstrated during the experimental period. Evidence for a natural loss of neurons during the morphogenesis of the superior cervical sympathetic ganglion is presented.

Newt forelimbs were unilaterally amputated and Beta-amino propionitrile (BAPN) was added to the water in which the newts were maintained. Sixty-three days after amputation, animals were injected with either 3H-proline or 3H-lysine. Forelimbs distal to the elbow of both amputated and non-amputated sides were removed 72 hours later. Uptake of 3H-proline and 3H-lysine in whole limbs was assessed by liquid scintillation and in cartilage cells and matrix by autoradiography. Amputation was a potent stimulus to both collagen formation and maturation during regeneration. BAPN reduced the stimulatory effect of amputation on collagen formation but not on its maturation. Collagen synthesis and maturation are independent events and, in intact non-regenerating limbs, BAPN adversely affected collagen maturation while collagen synthesis was unaltered.

Osteoblastic activity in the rat femur was assessed following sympathectomy by injections of guanethidine sulfate from birth to 14 days of age. At ages 30, 45 and 90 days, osteogenesis was monitored by quantitative autoradiography using 3H-proline. Grain counts over periosteal osteoblasts of the femoral diaphysis showed a significant reduction in the uptake of 3H-proline in sympathectomized rats. The results indicate that the sympathetic innervation of bone influences osteoblastic activity and provide support for a role of the autonomic nervous system in the regulation of bone formation.

BAPN (0.1 mg/day) was injected into chick embryos for 4 days starting on the 7th day of incubation. On the 11th day, the embryos were administered either 3H-proline or 3H-lysine. 36 h later, the incorporation of each isotope by the periosteal osteogenic cells as well as into bone matrix was investigated by autoradiography. The incorporation of the two isotopes into whole bones was assessed by liquid scintillation counting. 3H-proline incorporation into the cellular or matrical compartments was unaffected by treatment. As compared to the controls, 3H-lysine label in BAPN-treated embryonic bones was significantly higher in the cellular compartment but was reduced over the bone matrix. The data provide the first direct morphological evidence that BAPN probably induces certain changes in the maturation of collagen involving lysyl residues which result in an inhibition of cross-linkage formation in collagen.

The effects of cold-stress and hibernation on bone dynamics in the femurs of hamsters were investigated using histometric analyses. Control animals were maintained at 27 degrees C for 90 days; experimental animals were kept at 5 degrees C and hibernated for 7, 15, 21, 50, or 90 days. Histometric analyses of cross sections indicated that bone diameter and cortical thickness at the femoral midshaft increased after 83 days of extreme cold and 7 days of hibernation but decreased significantly after 69 days of cold stress and 21 days of hibernation. Osteoporosis was evident although the number of osteons per unit area of bone increased during hibernation. An initial decrease in the number of non-Haversian longitudinal vessels per unit area of bone was seen in experimental animals which was apparently related to a corresponding reduction in cortical thickness. Lacunar area increased in these animals, suggesting that osteocytic osteolysis may be a significant mechanism for calcium regulation during hibernation.

This report presents circadian rhythms in cell proliferation of alveolar bone periosteum and cementum of the maxillary first molars of male 5-week-old BNL, Swiss albino mice which were maintained on a 12 hr light/dark cycle. Mice were injected with 3H-TDR (luCi/gm. body wt.) 1 hr prior to sacrifice and killed every 3 hrs for 24 hrs starting at 9 a.m. Maxillae were decalcified, routinely processed histologically and autoradiographs prepared. Cell labeling indices of alveolar bone and cementum mesial to the first molar were determined. Alveolar bone periosteal and cemental cells show circadian rhythm in their DNA synthetic processes. Peaks in percent labeling exhibit higher values than previously reported for nontraumatized, normal dental periosteum and cementum. While the outer periosteum reveals a single 24 hr peak (6 p.m.), inner periosteum and cementum reveal two ultradian peaks 9 to 12 hrs apart involving both light and dark periods. Rodents are nocturnal, but high peaks are also evident in the light periods, consequently, not all peaks are synonymous with the period of animal activity and feeding. Although the single daylight peak of the outer periosteum may indicate growth of that surface at night to about noon, the double peaks exhibited by inner periosteum and cementum indicate light/dark, continuously active surfaces in terms of DNA synthesis and growth.

Sympathectomy was carried out in rats by injections of guanethidine-sulfate from birth to 14 days of age. At 45 days of age, the activity of osteoblastic cells was monitored by 3H-proline autoradiography. Effectiveness of sympathectomy was verified by light-microscopic examination of superior cervical and celiac ganglia. Grain counts over periosteal osteoblasts of the femoral diaphysis and osteoblasts mesial to the first molar in the mandible demonstrated a significant reduced uptake of 3H-proline in the sympathectomized rats. The data provide direct evidence of sympathetic influence on osteoblastic activity and suggest that sympathectomy may result in the loss of a trophic influence which is important in the regulation of osteogenesis.

The uptake of [3H]-proline was monitored by quantitative autoradiography at 30, 45 and 90 days of age. Grain counts in sympathectomized rats did not vary significantly from control values at any time. Thus the sympathetic nervous system does not influence the metabolic activity of these cells, which agrees with morphologic evidence that the innervation of the rat incisor may not be autonomic.

Intracellular labeling of DNA and RNA after H3-uridine administration was investigated autoradiographically during aging. Five to 78 weeks old mice were injected with 5 muCi of H3-uridine/gm of body weight and were killed from 15 minutes to 30 days later. Five mum decalcified sagittal sections of femora were treated with RNAase, DNAase or appropriate buffers. Autoradiographs were prepared and grain counts were made over diaphyseal periosteal osteoblasts. Both DNA and RNA incorporated H3-uridine. RNA label was 88 to 95% of the total cell label. DNA labeling ranged from 2 to 5%. DNA labeling appeared slightly increased after longer exposure to H3-uridine, whereas, RNA labeling remained relatively unaltered. With increasing age, incorporation into DNA decreased, whereas, RNA label showed a slight increase. A variable amount of non-specific label was undigested by either enzyme and may reflect insoluble conversion and/or degradation products. Apparently, some conversion of uridine into a DNA precursor occurs without loss of tritium label, thus rendering uridine less than totally specific for RNA. Nevertheless, the uptake of H3-uridine is largely indicative of RNA biosynthesis especially in skeletal cells that are not normally highly proliferative.

Pituitary gonadotrophin started increasing with gonadosomatic index from preparatory phase but increase in serum gonadotrophin became evident from prespawning phase. However, their peaks were noticed in spawning phase. During other phases of reproductive cycle their values were low except for female pituitary gonadotrophin potency which remained comparatively high during postspawning phase. An increase in ovarian and decrease in testicular lipid started from preparatory phase which continued till spawning phase. Liver lipid in either sex decreased during prespawning and spawning phases. Lipid level was low in ovary but was high in testis and liver during the remaining period of the year. Liver cholesterol was low during spawning and high in prespawning phase whereas serum cholesterol was low during prespawning and spawning phases and remained high during other and peak was recorded during spawning phase. Testicular cholesterol was low during preparatory and postspawning phases and high during the rest of the period of reproductive cycle.

A specific red cell adhesion test was done in 243 patients with carcinoma of the cervix uteri and showed the presence of isoantigens in only 27.16% of the patients with infiltrating squamous cell carcinoma. There was a gradual loss of isoantigens during the development of carcinoma. The test can be usefully employed in studying the evolution of the disease. The negativity of the test was found to increase as clinical severity of the disease increases. Also, the highest percentage (57.57%) of retained isoantigen was found in large-cell nonkeratinizing carcinoma, a well-differentiated type for the cervix. Follow-up studies suggest that the loss of antigen indicates probably metastasis and a poor prognosis.

Twenty-four LSH and LVG strain golden hamsters, Mesocricetus auratus, were used. Experimental animals were maintained at 5 C and allowed to hibernate. Control animals were kept at 27 C. Six animals (3 experimental, 3 control) were injected subcutaneously with 1 microCi of 3H-proline/gm body wt. (Spec. act. 3 Ci/mM) after hibernation lasting 12 hours, 1 day, 3 days, or 7 days. Animals were killed 1 hour after injection and autoradiographs were prepared from 5 microns thick decalcified sections of femurs. A greater number of endosteal cells were labeled than periosteal cells and also exhibited a greater magnitude of labeling throughout the study. Differences between endosteal and periosteal cells both in percentage of cells labeled and magnitude of labeling were maximum in control animals and progressively decreased with increasing periods of hibernation. A reduction in synthesis of matrix proteins during the early period of hibernation was seen and was attributed to a significant reduction both in average cell activity and in the number of active cells during hibernation. The latter phenomenon apparently made a large contribution to the reduced matrical synthesis. 3H-proline uptake by osteoblasts probably reflects the reduced requirements of matrical synthesis during hibernation.

Five-week-old BNL male mice were maintained on a 12-h light/dark cycle, subcutaneously injected with [3H]-thymidine 1 h before death and killed every 3 h for 24 h. Autoradiographs were made from demineralized, paraffin-wax embedded sagittal sections of maxillae. The labelling index was calculated for fibroblast-like cells of the periodontal ligament mesial to the first molar. A bimodal distribution of labelled cells was seen. Labelling index was highest at 0900 h (light period); a second, lower, peak was seen at 2400 h (dark period). Cell proliferation was significantly increased during the light period. The increased activity during the dark period may represent a superimposed secondary, ultradian, rhythm, differences in periodontal cell subtypes or may be related to the feeding and activity cycle of the mouse. Thus there is a 24-h cyclic rhythmicity in the proliferation of periodontal-ligament cells in the mouse.

The hypothalamo-hypophysial neurosecretory (HN) complex of Trichogaster fasciatus is described with the help of in situ staining technique and tissue sections. The neurons of the nucleus preopticus (NPO) give rise to fine neurosecretory axons which form the left and right main tracts. The bulk of the tracts come laterally and enter the middle portion of the neurohypophysis. However, some of them spread out and penetrate the rostral neurohypophysis as well. Hypophysial artery contributes to the formation of primary capillary plexus (PCP) which extends from the subterminal region to the extremity of the anterior neurohypophysis. Structurally, the subterminal region and the anterior neurphoyophysis can be compared to the median eminence (ME) of tetrapods as it is differentiated into ependymal, fibrous and reticular layers. Also, these areas have aboundant neurosecretory and silver positive axons suggesting the possibility of direct transmission of neurohormones into the blood.

During the last one-third of their gestational period, lathyritic rats incorporate significantly lower amounts of Sr85 as revealed by whole body counting techniques. This difference was maximum at term. The study provides evidence for lathyritic disturbance in the initial phases of mineralization of hard tissue matrices.

Articular cartilage is known to have limited ability to heal once injured, and attempts to heal lesions in cartilage have yielded equivocal results. The following experiments were performed to investigate healing in cartilage transplantation of chondrocytes grown in vitro. The knee joint of the New Zealand White rabbit was used as the experimental model. An initial baseline study was made to determine the intrinsic capability of cartilage for healing defects that do not fracture the subchondral plate. A second experiment examined the effects of autologous in vitro grown chondrocytes on the healing rates of these defects. The results were evaluated by qualitative and quantitative light microscopy. In control defects not grafted with chondrocytes, 6 weeks after the initial defect was created, there was little repair. Macroscopic and histological findings were consistent with an osteoarthritic pathology such as synovitis and "cell nests." Macroscopic results from grafted specimens displayed a marked decrease in synovitis and other degenerative changes. Defects which had received transplants had a significant amount of cartilage reconstituted (82%) compared to ungrafted controls (18%). Controls showed a healing rate comparable to that obtained in the initial baseline study.

The pituitary of Trichogaster fasciatus is devoid of a distinct stalk and is closely attached to the floor of the brain. The third ventricle is in wide communication with the anterior neurohypophysis adjacent to the pars distalis. The subterminal region of the hypothalamus and the anterior neurohypophysis forms the median eminence. Structurally this region can be compared to the median eminence of tetrapods as it is differentiated into ependymal, fibrous and reticular layers. A close morphological contact between the stainable neurosecretory and silver positive axons with the capillary plexus and accumulation of neurosecretory material around the capillary network suggest the presence of an incipient tetrapodan type of median eminence in this species.

In Ompok bimaculatus the neurosecretory axons of both the pars magnocellularis and pars parvocellularis component of the nucleus preopticus contribute to the formation of the left and right main tracts. At rostral levels, one third of the tracts are loosely built forming a king of curtain, while they become more compact at caudal levels. The caudal two thirds of the main tracts give off several pairs of lateral tracts which join at the midline to form the paired median tracts. The median and the main tract jointly enter the pituitary as a common tract which, on entering the proximal pars distalis, separates into two and enters the pars intermedia. The hypothalamic and the hypophysial arteries take their origin from the internal carotid artery. The former contribute to the formation of the primary capillary plexus of the median eminence, whereas the latter enter the pituitary directly and ramify in the neuroadeno-interface. The primary capillary plexus is in close topographical contact with the neurosecretory axonal complex where the median and common tracts are formed. At this site at least some axons might have their endings on the capillary plexus. Thus, this region my be comparable in structure to the median eminence of the tetrapods. The neurons of the nucleus lateralis tuberis of O. bimaculatus are AF-positive. The infundibular cavity extends into the main neurohypophysial trunk and is lined by ependymal cells like the third ventricle.

Five-week-old Brookhaven National Laboratory (BNL), Swiss-albino male mice were maintained on a 12-hour light/dark cycle and were subcutaneously injected with 3H-thymidine (1 micro Ci/gm body weight) one hour prior to sacrifice. Twenty-four mice (three each time-period) were killed at 3 hour intervals for 24 hours. Autoradiographs were prepared from 5-micron thick paraffin embedded decalcified sections of maxillary first molars and surrounding tissues. Labeling index was determined over the cells of the basal layer of the gingival epithelium. Crevicular and crestal gingival epithelium revealed a circadian rhythmic pattern in DNA synthesis in which two peaks were evident. Peak labeling of 5-week-old mouse gingiva exhibited a higher value than previously reported for nontraumatized gingiva. Rodents are nocturnal, as was peak activity, but a second peak is also evident in the light period. Consequently, not all peaks are synonymous with the period of animal activity and feeding. The observed continuous high labeling indices represent a significant potential of gingival epithelium to replenish its cells in response to physiological wear and tear.

The inferior alveolar nerve was unilaterally resected in 30-day-old mice; other animals were unilaterally sham-operated. At 15, 30, 60, 90, or 150 days after surgery, the mice wee injected with 2 muCi of 3H-proline (sp. act. 1.0Ci/mM) per g of body weight and killed 15, 30, or 60 min later. Autoradiographs were prepared from 5 micron decalcified sagittal sections of mandibles and grain counts made over periosteal osteoblasts mesial to the first molar. In denervated mandibles, osteoblasts incorporated less isotope compared to controls with differences being maximal at the early intervals. These differences became attenuated with time, possibly due to an intrinsic compensatory mechanism, secondary to neurotrophic regulation.

Regeneration and reorganization of the proximal cut end of the pituitary stalk is demonstrated in Ompok bimaculatus with the aid of in situ staining technique. The lesioned end exhibited an increase of axonal density and some axons became prominent by their uncontrolled growth. In few instances the cut ends were reorganized into a neurohypophysis-like organ.

Sympathectomy was carried out in 4-week-old Sprague-Dawley rats by unilateral surgical removal of the superior cervical ganglion. Sham-treated rats served as controls. All rats were injected with tetracycline hydrochloride at surgery as well as 36 hr prior to sacrifice. Rats were killed at 7, 14, or 21 days following sympathectomy. Mandibular periosteal and endosteal surfaces were analyzed by fluorochrome morphometry. Osteoclasts were identified by acid phosphatase staining, and incisor and molar root sockets were analyzed morphometrically. Following sympathectomy, periosteal and endosteal apposition as well as the rate of mineralization were significantly lower. At the same time, a significant increase in the number of osteoclasts per socket as well as in active and inactive bone resorption surfaces was also seen. All parameters, however, returned to normal values 2-3 weeks after sympathectomy. The data provide the first direct quantitative evidence that sympathetic neurons modulate bone resorption and bone remodeling in vivo.