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PubMed1990

[The clinico-pathological studies on the influence of immediate root canal filling after formalin guaiacol was applied on the extirpated pulp surface].

The method of immediate root canal filling following vital pulp extirpation involves many problems to be solved clinically. Therefore, the present study was performed to increase the clinical usefulness by applying formalin medicine in the root canal before immediate root canal filling after vital pulp extirpation. Group 1 (the group of applying formalin tricresol or formalin guaiacol on the intentionally exposed pulp tissue) Group 2 (pulp extirpation). This study is based upon 95 human permanent teeth with noninfected pulps in patients ranging in age from 16 to 43 years. Under local anesthesia the experimental teeth were isolated with cotton rolls. The pulp was intentionally exposed during the preparation of the Ingle's cavity with diamond instruments mounted on a high speed air turbine. The cavity and exposed pulp surface were cleaned with Neo-cleaner (10% Hypochlorite) and oxydol, and then dried using an absorbent material. One of the experimental medicines, which had been saturated into phi 2mm cotton pellet, was applied on the exposed pulp tissue. The cavity was filled with gutta-percha and amalgam. Under local anesthesia, the pulp was intentionally exposed in the same way as mentioned above. After removal of pulp tissue, root canals were cleaned with oxydol. Root canals were filled with Calvital (CV) in 15 cases. Following insertion of sterilized paper point soaked in the solution of formalin guaiacol (FG) or formalin tricresol (FC) for 5 minutes, root canal filling with Calvital was carried out in 20 cases. The experimental teeth were clinically observed at various intervals, and then extracted. After fixation in 10% formalin solution, the teeth were decalcified using nitric acid and embedded in celloidin. The serial sections were stained with hematoxylin and eosin and observed histopathologically. Group 1. 1. Kinds of clinical discomfort observed in this investigation were as follows. FG: Spontaneous pain (25.0%), Percussion discomfort (5.0%). FC: Spontaneous pain (35.0%), Percussion discomfort (35.0%). 2. Clinical results were as follows. FG: 14 cases (70.0%) out of 20 were evaluated as good, 6 cases (30.0%) as fairly good, and none as bad. FC: 11 cases (55.0%) out of 20 were evaluated as good, 9 cases (45.0%) as fairly good, and none as bad. 3. Histopathological changes observed in this investigation were as follows. 1) Hyperemia, 2) Hemorrhage, 3) Round cell infiltration, 4) Suppurative inflammation, 5) Coagulation necrosis, 6) Atrophy, 7) Cicatrization. Group 2. 1. Kinds of clinical discomfort observed in this investigation were as follows. CV: Spontaneous pain (20.0%), Percussion discomfort (20.0%). FG: Spontaneous pain (30.0%), Percussion discomfort (15.0%). FC: Spontaneous pain (30.0%), Percussion discomfort (30.0%). 2. Clinical results were as follows.

Adolescent↗
PubMed1981

Prophylactic cefazolin in gastric bypass surgery.

Because surgery in obese patients is associated with a high risk of infection, gastric bypass procedures offer an excellent opportunity to test the efficacy of prophylactic antibiotics. Accordingly, a double-blind prospective trial of prophylactic cefazolin was carried out in 53 consecutive patients who underwent gastric bypass surgery for morbid obesity. The patients were randomized to two treatment arms: (1) cefazolin intravenously, 1 gm 2 hours prior to surgery, at induction of anesthesia, and then 0.5 gm every 6 hours for 48 hours, or (2) an indistinguishable placebo of 5% dextrose at identical intervals. Serial cultures were taken at operation and in the postoperative period. Antibiotic levels of fat were measured by tissue extraction and B. subtilis assay. After surgery, patients were monitored for infection by clinicians unaware of their random assignment group. The study was terminated and the code broken when it was evident that wound infections were increased to a statistically significant difference in one arm of the study. The brief perioperative administration of cefazolin reduced the incidence of wound infection from 21% to 4% (P less than 0.05) and the incidence of urinary tract and pulmonary infections from 17% to 0% (P less than 0.05). Tissue levels of antibiotics confirmed adequate dosages in the test subjects. The advantages of prophylactic administration of cefazolin for gastric bypass procedures are clearly demonstrated in this study. This confirms other reports which have shown prophylactic antibiotics to be useful in a variety of procedures. These studies suggest the need to reconsider the traditional opposition to prophylactic antibiotics and to determine whether perioperative antibiotics should be used routinely in all major operations.

Adult↗
PubMed2002

Histomorphometric analysis of rat alveolar wound healing with hydroxyapatite alone or associated to BMPs.

Several materials and techniques have been proposed to improve alveolar wound healing and decrease loss of bone height and thickness that normally follow dental extraction. The objective of this research was the histologic analysis of bone morphogenetic proteins implanted into dental alveoli of rats after extraction. A total of 45 adult male Wistar rats were divided into three groups of 15 animals each: control (no treatment), implanted with pure hydroxyapatite (HA, 3 mg) and implanted with hydroxyapatite plus bone morphogenetic proteins (HA/BMPs, 3 mg). Five animals from each group were sacrificed at 7, 21 and 42 days after extraction for the histometric analyses of the osteoconductive potential of hydroxyapatite associated or not with BMPs. After dissection, fixation, decalcification and serial microtomy of 6-micron thick sections, the samples were stained with hematoxylin-eosin for histologic and histometric analyses. Both HA and HA/BMPs caused a delay in wound healing compared to control animals, evaluated by the percentage of bone tissue in the alveoli. The treatment with HA/BMPs had the greatest delay at 21 days, even though it produced values similar to the control group at 42 days. The materials did not improve alveolar repair in the normal period of wound healing and the association of HA/BMPs did not have osteoconductive properties with granulated hydroxyapatite as the vehicle.

Alveolar Bone Loss↗
PubMed1980

[99mTc-BIDA: functional parameters in the differential diagnosis of obstructive and parenchymatous jaundice (author's transl)].

75 Patients were examined with 99mTc-BIDA in order to find a reliable method of differentiating between obstructive and parenchymatous jaundice. Serial scans, repeated recordings of plasma radioactivity and external measurements over a temporal and a thigh region were taken between 1 and 30 min after injection. Serum half life of radioactivity, extraction coefficient and clearance rate, calculated from the first exponential slope over the temporal region curve, differed significantly in obstructive as compared to parenchymatous diseases and normals. In patients with extrahepatic obstruction the curves over the temporal and the thigh region differed; within the first 30 min the thigh values tend to increase. Clearance and extraction coefficients calculated from the third exponential slope of the plasma curve were significantly lower in obstructive jaundice than in other groups, although the great variation in these values did not allow a reliable differentiation in every patient. However, reliable results were obtained when these parameters were considered together with serial hepatic images.

Adult↗
PubMed1996

Progressive cerebral atrophy in multiple sclerosis. A serial MRI study.

Recent studies of the spinal cord and cerebellum have highlighted the importance of atrophy in the development of neurological impairment in multiple sclerosis. We have therefore developed a technique to quantify the volume of another area commonly involved pathologically in multiple sclerosis: the cerebral white matter. The technique we describe extracts the brain from the skull on four contiguous 5 mm periventricular slices using an algorithm integrated in an image analysis package, and quantifies their volume. Intra-observer scan-rescan reproducibility was 0.56%. We have applied this technique serially to 29 patients with multiple sclerosis selected for an 18-month treatment trial with a monoclonal antibody against CD4+ lymphocytes (deemed clinically ineffective). A decrease in volume beyond the 95% confidence limits for measurement variation was seen in 16 patients by the end of the 18-month period. The rate of development of atrophy was significantly higher in those who had a sustained deterioration in their Kurtzke expanded disability status scale (EDSS) score compared with those who did not (respective means: -6.4 ml year-1 and -1.8 ml year-1, P < 0.05) but in both groups these changes differed significantly from baseline (P < 0.05). Baseline T2 lesion load, change in T2 lesion load over 18 months and the volume of new gadolinium enhancing lesions on monthly scans for the first 10 months showed no correlation with the development of atrophy. This study demonstrates that progressive cerebral atrophy can be detected in individual patients with multiple sclerosis, correlates with worsening disability and gives additional information to that obtained with conventional MRI. The effect of putative therapies aimed at preventing disability could be objectively assessed by this measure.

Adult↗
PubMed2003

High frequency of resistant viruses harboring different mutations in amantadine-treated children with influenza.

Clinical samples from 15 amantadine-treated children were collected serially-before, during, and/or after treatment-and were studied to determine the actual prevalence, timing, and clinical implications of M2 mutational events. After viral RNA extraction and reverse-transcriptase polymerase chain reaction amplification of the viral RNA encoding the M2 protein, the products were cloned into plasmids, and their sequences were determined. Five mutations known to confer amantadine resistance in clinical samples were identified in 12 (80%) of 15 evaluable patients, and 9 patients had >1 (2-4) mutant virus. The pattern of emergence of mutant strains was clarified from the study of 6 patients with at least 4 serial samples. Although viruses with M2 mutations tended to become the dominant populations, in 2 cases, wild-type viruses became dominant after decreasing to low levels. These results suggest that resistant viruses emerge in a much higher proportion of amantadine-treated patients than has been suggested by previous studies.

Adolescent↗
PubMed2003

Comparison of allergen-induced late inflammatory reactions in the nose and in the skin in house dust mite-allergic patients with or without asthma.

BACKGROUND: It remains to be established which factors contribute to the occurrence of asthma in allergic individuals. We hypothesized that differences in the late allergic inflammatory reaction to allergen between asthmatic and non-asthmatic house dust mite-allergic individuals might contribute to the difference in the clinical presentation of allergy. AIM: To compare allergen-induced changes in parameters for cellular inflammation during the phase of the late allergic reaction in the skin and nose, in house dust mite-allergic individuals with or without asthma. MATERIAL AND METHODS: Nasal and dermal allergen challenges with house dust mite (Dermatophagoides pteronyssinus) extract were performed in 52 house dust mite-allergic individuals, of whom 26 had mild to moderate persistent asthma and 26 had perennial rhinitis without current or past asthmatic symptoms. Serial nasal lavage samples were analyzed for the presence of inflammatory cells (eosinophils and neutrophils) and soluble markers associated with cellular inflammation [interleukin-5 (IL-5), interleukin-8 (IL-8), eosinophil cationic protein (ECP) and myeloperoxidase (MPO)]. Macroscopic late phase skin reactions were studied after intracutaneous skin tests with house dust mite extract. RESULTS: Fixed dose nasal allergen provocation elicited a similar degree of immediate allergic reaction as judged by plasma protein exudation and histamine concentrations in asthma and non-asthmatic rhinitis. Subsequently, no differences between groups were found during the phase of the late allergic reaction (4-24 h) in inflammatory cell influx, plasma protein leakage, ECP or MPO. Likewise, there were no differences in levels of chemotactic cytokines IL-5 and IL-8. In agreement with the results of nasal challenge, the late skin reaction after dermal challenge with a fixed allergen dose and after an allergen dose 10,000 times above the skin threshold for an early skin reaction did not differ between the groups. CONCLUSION: House dust mite-allergic patients with or without asthma have very similar late allergic inflammatory reactions in the skin and in the nose after allergen challenge. Hence, it is unlikely that the occurrence of pulmonary symptoms in asthma is explained by a general tendency of asthmatics to have an enhanced late allergic cellular inflammatory response. Nasal and dermal allergen provocations are adequate models to study allergen-induced inflammation but probably lack the pivotal link which is essential for the development of asthma.

Adolescent↗
PubMed1997

Cultivation of rabbit corneal epithelial cells in serum-free medium.

PURPOSE: To establish conditions for cultivation, serial growth, and normal differentiation of corneal epithelial cells in serum-free medium (SFM). METHODS: Rabbit corneal epithelial cells were co-cultured with lethally treated 3T3-cell feeder layers. Instead of serum, medium was supplemented with serum albumin, hormones, and other additives. Cell growth was quantitated spectrophotometrically with a new rhodamine-B staining protocol with a sensitivity range of 5 X 10(3) to 1 x 10(5) cells/cm2. Keratin expression was analyzed by immunostaining or sodium dodecyl sulfate-polyacrylamide gel electrophoresis of cell extracts. RESULTS: In SFM, without growth factors, cells grew no more than six to eight doublings, but when 10 ng/ml epidermal growth factor were added, serial transfer was possible, and epithelial cells grew to up to 18 to 20 doublings (three cell passages). Two cell colony types were seen: One type was composed of nonstratified proliferating cells, and the other of stratified cells expressing high levels of the differentiation-linked keratins K3 and K12. Confluent cultures formed a four- to five-layer stratified epithelium whose suprabasal cells were stained with anti-K12 antiserum. Acidic and basic fibroblast growth factors and epidermal growth factor reduced the expression of keratins K3 and K12. Transforming growth factor-alpha and epidermal growth factor led to the highest stimulation of cell proliferation. Limbal, peripheral, and central corneal epithelial cells showed similar clonal growth abilities, but colony size was larger for cells derived from limbal epithelium. CONCLUSIONS: These SFM conditions support the serial transfer, normal differentiation, and formation of typical corneal epithelium by cultured corneal epithelial cells and are useful in studying and assaying a variety of cytokines and compounds that modulate corneal epithelial cell proliferation and differentiation.

3T3 Cells↗
PubMed1998

Repeated aerosol exposure to small doses of allergen. A model for chronic allergic asthma.

To improve our understanding of the pathophysiology of chronic allergic asthma, we mimicked natural allergen exposure by giving tiny doses of dust-mite extract (equivalent to estimated daily exposure in a typical bedroom) in three weekly sessions for 4 wk. Nine mild asthmatic adults who were highly sensitive to dust-mite allergen participated in the study. Serial assessments of bronchial reactivity by methacholine challenge, pulmonary function, symptoms, and bronchodilator requirements were obtained. Seven of nine subjects had a twofold or more (median: 6, range: 2.7 to 25) reduction (p = 0.008) in PC20, after which saline inhalations were substituted for dust-mite extract. Bronchial reactivity returned to normal within 2 to 3 wk after cessation of dust-mite inhalations in all but one subject. Predosing FEV1 dropped 10% over 4 wk of provocation (p = 0.001) and 7 of 9 returned to prestudy level within 2 wk after dosing was stopped. Late-phase responses were seen in 6 of 9 subjects. We conclude that repeated aerosol exposure to dust-mite allergen in doses comparable to natural bedroom exposure is sufficient to adversely affect pulmonary function and bronchial hyperractivity in sensitized individuals. These changes are rapidly reversible. This low-dose provocational strategy provides an attractive model for the experimental study of allergic asthma. Arshad SH, Hamilton RG, Adkinson NF, Jr. Repeated aerosol exposure to small doses of allergen: a model for chronic allergic asthma.

Adolescent↗
PubMed1977

Corneal edema: iris-clip lens implantation and simple intracapsular extraction compared.

Corneal edema following intracapsular lens extraction and iris-clip lens implantation was compared by assessing corneal thickness and epithelial edema. In a retrospective study the corneal thickness of twenty patients who had intracapsular lens extraction in one eye only was compared with twenty-six patients with iris-clip lens implants in one eye. There was no significant increase in corneal thickness in the operated eye in either group. In a prospective randomized controlled study, a smaller number of patients, had serial measurements of corneal thickness pre- and postoperatively. There was an increase in thickness in the immediate postoperative period for both groups. However, there was no significant difference between eyes which had simple extraction and those which had implants. The implanted eyes however had greater mean increase endothelial trauma in the initial period, compared to eyes with cataract extraction alone.

Aged↗
PubMed2001

Bioequivalence evaluation of two brands of cefaclor 500 mg capsules: quantification of cefaclor using solid phase extraction technique.

OBJECTIVE: To assess the bioequivalence of two cefaclor 500 mg capsule formulations, and to develop a new high performance liquid chromatographic (HPLC) method using solid phase extraction technique for the quantification of cefaclor in human plasma. METHOD: An open, randomized, two-way, crossover trial with a one-week washout period in 25 healthy volunteers. The two commercial brands used were Recocef(Julphar, United Arab Emirates) as test and Ceclor(Eli Lilly, UK) as reference product. The drug was administered with 240 mL of water after a 10-h overnight fast. After dosing, serial blood samples were collected for a period of 8 h. Plasma harvested from blood was analysed for cefaclor by a new HPLC method using a solid phase extraction technique. The limit of detection of cefaclor was 17.6 ng/mL; average recovery was 96.5%; the intraday CV was less than 8% and interday CV was less than 13%. Various pharmacokinetic parameters, including AUC0-t, AUC0-infinity, Cmax, Tmax, T1/2, and Kel, were determined from plasma concentrations for both formulations. Statistical analysis (ANOVA and 90% confidence intervals) were applied to AUC0-t, AUC0-infinity and Cmax for bioequivalence evaluation of two brands. The new HPLC method with solid phase extraction circumvented the problem of mixed polarity of cefaclor and facilitated its extraction from the complex plasma matrix while keeping the background free from interference due to endogenous plasma compounds. RESULTS: No significant difference was observed between the two brands of cefaclor capsules. CONCLUSION: Recocef was judged bioequivalent to Ceclor and the two products can therefore be considered to be interchangeable in medical practice.

Adolescent↗
PubMed1995

Acute axonal Guillain-Barré syndrome with IgG antibodies against motor axons following parenteral gangliosides.

We studied 7 patients with an acute motor axonal Guillain-Barré syndrome (GBS), manifested 5 to 15 days after parenteral injection of a commercial ganglioside preparation given for nonspecific pain syndromes. The serum IgG and IgM antibody response to ganglioside was studied serially and the recognition of epitopes on the peripheral nerves and motor end-plates was examined using biotinylated IgG extracted from the patient's serum. Sera from 8 patients treated with the same ganglioside preparation who did not develop neuropathy and from 25 patients with classic GBS never treated with gangliosides were studied concurrently. All patients with ganglioside-related GBS had a rather severe axonal degeneration, incomplete recovery, and high IgG, but not IgM, antiganglioside antibody titers, ranging from 1:320 to 1:10,240. Seven (28%) of the 25 GBS patients had IgG antibody titers, ranging from 1:160 to 1:10,240. None of the ganglioside-treated patients who did not develop GBS and none of the 50 disease control subjects had IgG GM1 antibodies. Purified IgG from the patients with high GM1, antibodies, but not from the others, recognized epitopes at the nodes of Ranvier and the distal motor nerve terminals at the end-plate. We conclude that exogenous ganglioside injections can be immunogenic, triggering IgG antiganglioside antibodies with specificity for motor nerve-terminals. In some patients with axonal GBS such antibodies may be markers or mediators of axonal involvement.

Antibodies↗
PubMed1998

[Choroid neovascularization in age-related macular degeneration. Correlation of histological and fluorescence angiography findings].

BACKGROUND: Recent studies have raised confusion about the fluorescein angiographical and histopathological correlation of CNV. MATERIAL AND METHODS: The preoperative fluorescein angiograms of four patients with subfoveal CNV due to ARMD extracted by pars plana vitrectomy were classified as wellor ill-defined CNV and were correlated to the histopathologically (in serial sections) verrified CNV-location (subneuroretinal (= type II according to Gass) versus sub-RPE (type I according to Gass)). RESULTS: The locations of all four CNV could be classified by histopathological landmarks as there were RPE, BLD/drusen, and inner Bruchs membrane. Angiographically welldefined membranes were type II membranes according to Gass, whereas the ill-defined membrane represented type I. The CNV with well- and ill-defined borders consisted of type II and type I parts according to Gass. CONCLUSION: We find subneuroretinal locations of the well-defined CNV examined (type II membranes according to Gass). Correspondingly, ill-defined CNV or ill-defined parts of a CNV seem to be beneath the RPE (type I). The correlation of fluorescein angiography and histopathology should be studied in greater numbers of well- and ill-defined CNV.

Bruch Membrane↗
PubMed1997

Evaluating a possible pharmacokinetic interaction between remifentanil and esmolol in the rat.

Remifentanil (Ultiva) is a novel, ultra-short-acting opioid which has recently been approved for use as an analgesic during induction and maintenance of general anesthesia. Esmolol is a short-acting beta-blocker used during surgical procedures to reduce heart rate and blood pressure. Both drugs are metabolized by nonspecific esterases in the blood and other tissues and may be administered concomitantly during surgery. The goal of this study was to determine if coadministration of esmolol significantly alters the pharmacokinetics of remifentanil in the rat. Two groups of rats were dosed with remifentanil [25 micrograms/kg/min (n = 8)] and remifentanil plus esmolol [25 and 200 mg/kg/min (n = 7)] for 20 min. Cardiovascular measurements were collected continuously over the course of the study. Serial blood samples (12) were collected over 25 min into test tubes containing 0.5 mL of acetonitrile. Blood samples were extracted (liquid-liquid) with methylene chloride and then analyzed by a validated GC-MS assay. Compartmental data analysis was performed using PCNONLIN. The mean(+/- SD) for Cl and t1/2 observed in treatment I were 390(+/- 98) mL/min/kg and 0.69(+/- 0.27) min and in treatment II were 421(+/- 164) mL/min/kg and 0.56(+/- 0.22) min, respectively. Comparison of clearance, volume of distribution, and terminal half-life between the two groups showed that coadministration of esmolol had no significant (p < 0.05) effect on the pharmacokinetics of remifentanil in the rat.

Adrenergic beta-Antagonists↗
PubMed1998

Non-invasive diagnosis of pregnancy in wild black rhinoceros (Diceros bicornis minor) by faecal steroid analysis.

The objective of this study was to determine whether faecal progestagen measurement could be used to diagnose pregnancy in wild black rhinoceros cows. Immunoreactive 20alpha-progestagens were measured in faecal samples collected regularly (one or two times times per week) from pregnant and non-pregnant wild black rhinoceros females (n = 6) in Zimbabwe. Fresh dung piles deposited by the study animals were serially sampled during prolonged periods of tracking with local game scouts. Samples were stored frozen, and dried prior to methanol extraction. Immunoreactivity in faecal extracts was measured with a 20alpha-dihydroprogesterone enzyme immunoassay and was shown to reflect circulating progesterone concentrations. Mean concentrations of faecal 20alpha-progestagens during each month of gestation were significantly higher than faecal concentrations in non-pregnant animals (P<0.05), except during the second month of gestation. Faecal 20alpha-progestagens remained 5-10 times higher than concentrations in non-pregnant animals from the 4th to 15th month of gestation. It was concluded that regular non-invasive reproductive monitoring of black rhinoceros in the wild was possible and that pregnancy could be accurately diagnosed from the measurement of 20alpha-progestagens in faecal samples. The use of this technique in wild black rhinoceros populations will offer new perspectives for in situ management of this endangered species.

20-alpha-Dihydroprogesterone↗
PubMed1992

Upregulation of O6-alkylguanine-DNA-alkyltransferase expression and the presence of double minute chromosomes in alkylating agent selected Chinese hamster cells.

Chinese hamster V79 lung fibroblasts are sensitive to the toxic effects of chloroethylating agents such as mitozolomide (Mz) and express very low levels (less than 2 fmol/mg) of the DNA repair enzyme O6-alkylguanine-DNA-alkyltransferase (ATase). These cells were subjected to selection by treatment with serially increasing doses of Mz. After each dose, the surviving population was expanded and ATase activity was determined in cell extracts. ATase specific activity increased stepwise and in cells surviving selection at 120 micrograms/ml Mz had reached 430 fmol/mg protein: polyacrylamide gel electrophoresis and fluorography showed the size of the ATase as 25 kDa. Cytological examination of these cells showed the presence of double minute (DM) chromosomes (mean approximately 3/cell) but no obvious homogeneously staining regions. In cells grown in continuous culture without further selection no marked decrease in ATase activity or DM frequency was observed. Karyotype analysis and DNA profiling confirmed that the parent and selected cells were of the same origin with, in the latter case, the probable loss or gain of a single restriction endonuclease site. No major differences were seen in the intensity of hybridization signals following Southern analyses of DNA from control and Mz selected cells using the human ATase cDNA as a probe. These results indicate that the ATase gene is not amplified in the Mz selected cells and suggest that increased ATase activity is a consequence only of increased transcription or translation of the ATase gene.

Animals↗
PubMed2004

Decline of serum human chorionic gonadotropin and spontaneous complete abortion: defining the normal curve.

OBJECTIVE: We sought to estimate a standard curve of serum human chorionic gonadotropin (hCG) decline that characterizes spontaneous abortion. METHODS: Data were extracted from a clinical database of women with symptomatic early pregnancies and nondiagnostic ultrasonography who required follow-up with serial hCG levels. The evaluation was restricted to women who had a pregnancy of unknown location, a decrease in serum levels, and who were ultimately diagnosed with miscarriage (a decrease in serum hCG to < 5 mIU/mL in the absence of surgical intervention or confirmation of products of conception after dilation and curettage). The starting point of the curve was the hCG concentration at presentation, with serial levels plotted until the time of definitive diagnosis. Semiparametric statistical techniques were used to characterize the shape of the curve. We present slopes for the decrease in log hCG levels and the projected rate of fall. RESULTS: Of the 1,543 patients, 710 were diagnosed with miscarriage. A quadratic curve for log hCG with a steeper rate of decline for large initial hCG values best described the pattern of change. One curve could not fully estimate the decline because the rate was dependent on the initial hCG level. In other words, more rapid decline was associated with a higher starting concentration. The rate of decline ranged from 21% to 35% at 2 days and 60% to 84% at 7 days, depending on initial hCG value. CONCLUSION: The rate of hCG decrease in spontaneous abortions is described by a quadratic profile, with a faster decline in hCG value with higher presentation levels. A rate of decline less than 21% at 2 days or 60% at 7 days suggests retained trophoblasts or an ectopic pregnancy.

Abortion, Spontaneous↗
PubMed1984

Selective cultivation of human melanocytes from newborn and adult epidermis.

Development of adequate culture systems for the human epidermal melanocyte is critical to further advances in pigment cell biology. We now report selective growth and long-term maintenance of melanocytes derived from both newborn and adult skin specimens. Disaggregated epidermal cell suspensions were plated in a hormone-supplemented medium containing cholera toxin and a hypothalamic extract treated to remove keratinocyte growth-promoting activity. After 3-4 weeks, pure melanocyte populations could be harvested and serially passaged up to 6 times over several months for a total of 10 or more cumulative population doublings in vitro. Electron microscopic studies revealed metabolically active cells with abundant melanosomes in various stages of melanization throughout the culture lifespan. Differences in size and number of melanosomes attributable to race of the tissue donor were readily apparent, and pigment content of melanocytes from both black and Caucasian donors appeared to increase with time in culture. Newborn melanocytes proliferated more rapidly and survived longer than did adult melanocytes, but there were no consistent morphologic differences as a function of donor age. Comparison of growth potential for the 3 major skin-derived cell types in this hormone-supplemented medium revealed striking specificity for melanocytes, with total elimination of keratinocytes over 1-2 weeks, and no fibroblast proliferation whatever in the absence of serum supplementation. This system promises to facilitate in vitro investigation of epidermal melanocytes in normal and diseased human skin.

Adult↗