Algas epífitas de Bajo Pepito, Isla Mujeres, Quintana Roo, México / Epiphytic algae from Bajo Pepito, Isla Mujeres, Quintana Roo, Mexico

A total of 96 epiphytic algae species were identified from Bajo Pepito, Quintana Roo, México. 60.4% (58) belonged to the Rhodophyta, 19.79% (19) to the Phaeophyta, 16.6% (16) to the Chlorophyta and 3.1% (3) to the Cyanophyta; 49 species (50.5%) were found only in one month, while Heterosiphonia crispella was found in all of the sampled months. That species provided the largest contribution to the biomass of epiphytes. During January we registered the greater biommass and richness of epiphytes species, coincidently with high values of host species cover and rainfall.

Se identificó un total de 96 especies de algas epífitas de Bajo Pepito, Quintana Roo, México; el 60.4% (58) pertenecieron a la división Rhodophyta, 19.79% (19) a la división Phaeophyta, 16.6% (16) a la división Chlorophyta y 3.1% (3) a la división Cyanophyta; 49 especies (51%) se presentaron solamente en un mes de muestreo. Heterosiphonia crispella se presentó en todos los meses de muestreo, y fue la que tuvo mayor contribución en la biomasa de epífitas. En enero se registró la mayor biomasa y riqueza de algas epífitas, lo cual coincidió con valores altos de cobertura de especies hospederas y precipitación pluvial.

[Epiphytic algae from Bajo Pepito, Isla Mujeres, Quintana Roo, Mexico]. / Algas epífitas de Bajo Pepito, Isla Mujeres, Quintana Roo, México.

A total of 96 epiphytic algae species were identified from Bajo Pepito, Quintana Roo, México. 60.4% (58) belonged to the Rhodophyta, 19.79% (19) to the Phaeophyta, 16.6% (16) to the Chlorophyta and 3.1% (3) to the Cyanophyta; 49 species (50.5%) were found only in one month, while Heterosiphonia crispella was found in all of the sampled months. That species provided the largest contribution to the biomass of epiphytes. During January we registered the greater biommass and richness of epiphytes species, coincidently with high values of host species cover and rainfall.

Aminoterminal propeptide of type I collagen and bone alkaline phosphatase in the study of bone metastases associated with prostatic carcinoma.

The aim of this work was to evaluate the usefulness of serum aminoterminal propeptide of type I collagen (PINP) in the early detection of bone metastases associated with prostatic carcinoma. The results were compared with those of bone isoenzyme of alkaline phosphatase (bAP). Levels of total alkaline phosphatase (TAP) and prostatic specific antigen (PSA), related to the existence of bone metastases, are also evaluated. Fifty-five male patients aged 70-80 years were studied. Nine presented a benign prostatic hyperplasia (BPH) and the rest clinically confirmed prostatic cancer. Cancer patients were classified in accordance with the staging grouping of the International Union Against Cancer/American Joint Committee on Cancer TNM 1992 Revision: stage 0 or BPH (n=9), I (n=6), II (n=12), III (n=18) and IV (n=10). According to this classification, patients of groups BPH, I, II and III have no evidence of metastases. Those of stage IV present any type of metastases. In the case of this work, all patients of group IV presented bone metastases. Some patients of group BPH, I and II were untreated. The rest of the patients were under treatment (radical prostatectomy, telecobaltotherapy or hormonal therapy) for a period of between 6 months and 15 years. Serum PSA (Quimioluminiscence, IMMULITE), PINP (RIA, Orion Diagnostica), bAP (IRMA, Tamdem R-Ostase, Hybritech), and TAP (autoanalyzer) were determined. We found the following sensitivities and specificities (relating the presence of bone metastases to values higher than the upper limit of normality and, in the case of PSA, to values higher than 100 microg/L): (1) PINP: 100% (10/10) and 87% (39/45), (2) bAP: 90% (9/10) and 82% (37/45), (3) TAP: 60% (6/10) and 93% (42/45), (4) PSA: 40% (4/10) and 100% (45/45). These results suggest that PINP and bAP are adequate biochemical markers of bone formation to be used in the detection of bone metastases in prostatic carcinoma, improving the sensitivity and specificity of TAP and PSA. With respect to PINP, bAP presents the disadvantage of its cross-reactivity with liver isoenzyme.

Variable efficacy of bone remodeling biochemical markers in the management of patients with Paget's disease of bone treated with tiludronate.

The aim of this work was to evaluate the response of different biochemical bone markers to tiludronate administration in Paget's disease of bone. Ten patients (five men and five women), 56-77 years old (67 +/- 6.5), were treated for 3 months with tiludronate tablets (400 mg/day). Bone formation markers: alkaline phosphatase (AP), bone alkaline phosphatase (bAP), osteocalcin (BGP), and procollagen I carboxyterminal propeptide (PICP) in serum; and bone resorption markers: serum cross-linked carboxyterminal telopeptides of type I collagen (ICTP), urinary hydroxyproline/creatinine (Hyp/Cr), pyridinoline/Cr (Pyr/Cr), and alpha-1 collagen chain products degradation (CrossLaps) were assessed. Samples were taken before and at monthly intervals for 3 months after treatment began. The results of the present work show that serum AP and bAP are sensitive and reliable biochemical markers of bone formation in the follow-up of tiludronate in this disease. Serum PICP shows less sensitivity than serum AP, and serum BGP is not indicated as biochemical marker in these types of studies. Urinary hydroxyproline seems to be the most reliable biochemical marker of bone resorption. More studies should be performed with urinary Pyr and CrossLaps determinations. Serum ICTP is not adequate for the follow-up of tiludronate treatment in Paget's disease of bone.

New biochemical markers of bone resorption derived from collagen breakdown in the study of postmenopausal osteoporosis.

The aim of this work was to perform a comparative study between three recently developed biochemical markers of bone resorption derived from collagen metabolism--(1) total urinary free pyridinolines (Pyr), (2) serum pyridinoline cross-linked carboxy-terminal telopeptides of type I collagen (ICTP) and (3) a urinary-specific sequence for a part of the C-telopeptide of the alpha 1 chain of type I collagen (CTX)--in the diagnosis and follow-up of postmenopausal osteoporosis. Results were also evaluated relative to the classical biochemical marker urinary hydroxyproline (Hyp). The study included 20 untreated osteoporotic postmenopausal women (OSP), age 60 +/- 6 years, range 46-69 years; 27 osteoporotic postmenopausal women treated (OSP-T) by cyclic therapy with disodium etidronate, 25-hydroxyvitamin D and calcium for a period between 3 months and 4 years (25 +/- 15 months), age 59 +/- 7 years, range 41-67 years; 17 osteopenic postmenopausal women, age 57 +/- 6 years, range 46 +/- 68 years; and 29 healthy control postmenopausal women, age 56 +/- 7 years, range 41-70 years. The diagnostic criterion for postmenopausal osteoporosis was a bone mineral density (BMD) (Hologic QDR-1000) in lumbar spine and/or femoral neck more than 2 SD below the mean value corresponding to an age- and sex-matched healthy control group. For inclusion in the osteopenic group BMD values had to be between 1 and 2 SD below the mean BMD value corresponding to the control group. We found a significant increase (p < 0.01) in the levels of Pyr/Cr and CTX/Cr (Cr = creatinine) in OSP patients with respect to the control group and we did not observe any significant difference between control and OSP-T or osteopenic women. It is interesting to note that there was a mean increase in CTX/Cr in OSP patients of 101% of the control values, while the mean increase found in Pyr/Cr concentration was only 33%. However, we did not find significant differences in the concentrations of ICTP and Hyp/Cr between groups. In a comparison of Pyr/Cr and CTX/Cr, urinary CTX showed the higher diagnostic accuracy, as can be deduced from the receiver operating characteristic (ROC) curves. CTX sensitivity was 40% with a specificity of 100%, whereas the sensitivity was 25% for urinary Pyr/Cr. In conclusion, the results of the present work suggest that in osteoporotic women CTX has the highest diagnostic accuracy among the markers of bone resporption studied.

Lack of correlation between levels of osteocalcin and bone alkaline phosphatase in healthy control and postmenopausal osteoporotic women.

The determination of bone alkaline phosphatase (bAP) by IRMA and the measure of intact osteocalcin (BGP) and/or different fragments by IRMA and/or RIA are new commercially available methods for the evaluation of osteoblast activity. The aim of this work was to study the possible correlation among serum bAP and levels of BGP measured by two different methods: an IRMA which only detects intact-BGP and a RIA which detects intact-BGP and carboxyterminal fragments (C-terminal BGP) in healthy post-menopausal control women and in a group of patients with post-menopausal osteoporosis. Serum samples from 42 consecutive osteoporotic postmenopausal women, aged 62 +/- 11 years, between 39-76, and 14 control women age matched, were drawn after an overnight fasting. Levels of total alkaline phosphatase (AP), bAP, intact BGP, and intact BGP and carboxy terminal fragments were measured. In both groups we found a significant linear correlation between the levels of AP and bAP (r = 0.79, p < 0.001) and intact-BGP and C-terminal BGP (r = 0.97, p < 0.001), but surprisingly we did not find a significant linear correlation between AP or bAP levels and BGP measured in any of the two methods. These results suggest that AP release from osteoblast vesicles and BGP synthesis in these cells are not necessarily simultaneous, reflecting different stages of osteoblast activity.

Serum concentrations of carboxyterminal cross-linked telopeptide of type I collagen (ICTP), serum tartrate resistant acid phosphatase, and serum levels of intact parathyroid hormone in parathyroid hyperfunction.

We have studied the levels of a new biochemical marker of bone resorption, carboxyterminal cross-linked telopeptide of type I collagen (ICTP), in 26 healthy control subjects, 15 patients with primary hyperparathyroidism (PHPT) and 17 patients with secondary hyperparathyroidism (secondary HPT). Levels of ICTP in PHPT and secondary HPT have been correlated with those of serum tartrate resistant acid phosphatase (TRAP), another biochemical marker of bone turnover, and with serum levels of intact parathyroid hormone (iPTH). The ICTP levels of the control group were 2.07 +/- 0.58 micrograms l-1, n = 26, range 1.3-3.2. They were independent of sex and age in the studied age range (30-62 years). The ICTP levels of PHPT patients were 3.5 +/- 3.5 micrograms l-1, mean +/- SD, range 0.5-12.2 micrograms l-1, significantly higher than those of control subjects (p < 0.05). We found a significant linear correlation between values of ICTP and iPTH levels (p < 0.01), between values of ICTP and serum activity of TRAP (p < 0.01) and between iPTH and TRAP levels (p < 0.01) in patients with PHPT. The ICTP levels in patients with secondary HPT were higher than those of patients with PHPT, 46 +/- 37 micrograms l-1, range 12-167 micrograms l-1 (p < 0.001) due to the impaired renal clearance of this peptide. We did not find a significant linear correlation between values of ICTP and iPTH levels in the serum of patients with secondary HPT, although we found a significant correlation between levels of ICTP and levels of TRAP, both biochemical markers of bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS)