Spectrum of cutaneous granulomatous lesions: A 5-year experience in a tertiary care centre in Sarawak.

INTRODUCTION: Granulomatous skin lesions can have various histopathological features leading to diagnostic confusion. The study aimed to determine the frequency and pattern of different granulomatous skin lesions. MATERIALS AND METHODS: This was a 5-year retrospective study done between April 2017 and March 2022 at Dermatology Department, Sarawak General Hospital. Subjects with a clinicopathological diagnosis of granulomatous diseases were included in the analysis. RESULTS: A total of 1718 skin biopsies were done during the study periods, with 49 (2.8%) confirmed granulomatous skin lesions. Most patients were aged 40-60 with a male predominance of 51%. Most of the skin biopsy samples were taken from the upper limb (36%). In this study, epitheloid granuloma was the commonest subtype (21, 43%) followed by suppurative granuloma (12, 24%), tuberculoid granuloma (8, 16%) and foreign body granuloma (5, 10%). The commonest aetiology of granulomatous skin lesions in our study was infections (30, 61%) followed by foreign body inoculation (8, 16%). Fungal infection was the most common infective cause, followed by cutaneous tuberculosis. CONCLUSION: The major cause of granulomatous dermatoses in developing countries is still infections, fungal and tuberculosis being the leading causes.

[Prostate health index for the diagnosis of prostate cancer in Asians in Macau with a PSA level of 4－10 µg/L].

OBJECTIVE: To evaluate the prostate health index (PHI) as a tool for the diagnosis of PCa with a PSA level of 4－10 µg/L and determine the best cut-off value of PHI. METHODS: Fifty-eight patients with a PSA level of 4－10 µg/L underwent transrectal ultrasound-guided prostatic biopsy in our hospital between April 2017 and June 2019. We constructed receiver operating characteristic (ROC) curves for the relationship of the biopsy results with the level of PSA, the ratio of ［－2ï¼½ proPSA to fPSA and PHI, and calculated the area under the ROC curves (AUC). RESULTS: Prostatic biopsy revealed 18 cases of PCa in the 58 patients (31.0%). Statistically significant differences were observed between the PCa and non-PCa groups in ［－2ï¼½ proPSA, %［－2ï¼½ proPSA and PHI, but not in tPSA, % fPSA and PSA-density. The AUCs of PSA, % fPSA, PSA-density, ［－2ï¼½ proPSA, %［－2ï¼½ proPSA and PHI were 0.556, 0.407, 0.533, 0.746, 0.751 and 0.774, respectively. The specificity of PHI was 27.50% (95% CI: 14.6%－43.9%), the highest among the above predictors at 90% sensitivity. By applying PHI to this cohort, 13 cases (22.4%) of unnecessary biopsy could be avoided. CONCLUSIONS: The application of PHI can increase the accuracy of PCa prediction and reduce unnecessary prostatic biopsy.、.

Effect of Severe Water Stress on Aspects of Crassulacean Acid Metabolism in Xerosicyos.

Xerosicyos danguyi H.Humb. (Cucurbitaceae) is a Crassulacean acid metabolism (CAM) species native to Madagascar. Previously, it was shown that when grown under good water conditions, it is a typical CAM plant, but when water stressed, it shifts to a dampened form of CAM, termed CAM-idling, in which stomata are closed day and night but with a continued, low diurnal organic acid fluctuation. We have now studied the kinetics of some metabolic features of the shift from CAM to CAM-idling under severe water stress and the recovery upon rewatering. When water is withheld, there is a steady decrease in relative water content (RWC), reaching about 50%, at which point the water potential decreases precipitously from about -2 or -3 bars to -12 bars. Abscisic acid (ABA) increases sharply at about 75% RWC. Stomata close, which limits CO2 uptake, and there is a dampened diurnal organic acid fluctuation typical of CAM-idling. Throughout an extended stress period to 50% RWC, there is no change in chlorophyll, protein, and ribulose bisphosphate carboxylase activity compared with the well-watered plants. Despite the fact that the tissue was already in CAM, the stress is accompanied by an increase in phosphoenolpyruvate carboxylase (PEPc) mRNA, extractable PEPc activity, and PEPc protein (such that the specific activity remained approximately constant) and a decrease in the apparent Km(PEP). It is not known if the changes in Km(PEP) in response to drought are related to or are separate from the increases in PEPc protein and mRNA. The changes in Km(PEP) could be in response to the decreased endogenous levels of organic acids, but evidently are not an assay artifact. The increases in PEPc protein and mRNA appear to be related to the water-stress treatment and may result from the increased concentration of ABA or the decreased levels of endogenous organic acids. When rewatered, the metabolism quickly returns to the well-watered control typical of CAM.

Fluorescence Quenching in the Varied Photosynthetic Modes of Portulacaria afra (L.) Jacq.

The kinetics of chlorophyll fluorescence were measured in Portulacaria afra (L.) Jacq. when the plants were functioning in either Crassulacean acid metabolism (CAM) or C(3)/CAM cycling (called cycling) modes, as determined by fluctuation in titratable acidity and gas exchange properties. Cycling plants showed primarily daytime CO(2) uptake typical of C(3) plants, but with a slight diurnal acid fluctuation, whereas CAM plants showed nocturnal CO(2) uptake, daytime stomatal closure, and a large diurnal acid fluctuation. Results from fluorescence measurements indicated no significant differences in photochemical quenching between cycling and CAM plants; however, sizable differences were detected in nonphoto-chemical quenching (q(n)), with the largest differences being observed during the middle of the day. Cycling plants had lower q(n) than CAM plants, indicating altered photosynthetic regulation processes. This q(n) difference was believed to be related to reduced internal CO(2) concentration in the CAM plants because of daytime stomatal closure and reduced deacidification rates in the late afternoon when most of the malic acid has been utilized. Experimentally, higher external CO(2) given to plants in the CAM mode resulted in a decline in q(n) in comparison to that measured in plants in the cycling mode. No changes were observed in photochemical quenching when CO(2) was added.

Ecophysiological comportment of the tropical CAM-tree Clusia in the field: II. Modes of photosynthesis in trees and seedlings.

Measurements were performed on leaves of Clusia rosea Jacq. trees in the moist central mountains (330 to 365 m above sea level) and at the dry south coast of St John Island (US Virgin Islands, Lesser Antilles). Seedlings of C. rosea were also studied in the central hills. During the study period (March 1989) all trees showed crassulacean acid metabolism (CAM), in which net CO2 uptake extended for a remarkably long time in the morning (phase II of CAM: until about 11 to 12 h) and contributed about 1/3 of total net CO2 -uptake. During the night (phase I of CAM) malic acid and citric acid were accumulated concurrently at a molar ratio of malic: citric acid of about 1.6. Internal recycling of respiratory CO2 was 20% of total CO2 fixed during the night. Water-use-efficiency (mol CO2 taken up: mol H2 O transpired) was 0.014 to 0.022. The pH of leaf-cell sap at the end of the dark period was 2.85. This would still allow an H+ -ATPase at the tonoplast to transport 2H+ into the vacuole per ATP hydrolysed when operating near thermodynamic equilibrium. Free sugars, glucose and fructose, and starch were used as precursors for the CO2 -acceptor phosphoenolpyruvate during the dark period; contributions of the two hexoses were about equal and together four-times that of starch. Xylem tensions showed increases of up to 8 bar during day-time. Leaf-sap osmotic pressures did not change significantly; the trend was a small decline during day-time. Among the seedlings, three different modes of photosynthesis were encountered, namely C3 -photosynthesis in terrestrial and in epiphytic seedlings, continuous stomatal opening and CO2 -uptake day and night in epiphytic seedlings, and CAM in seedlings growing in the tanks of Aechmea lingulata (L.) Baker.

Ecophysiological comportment of the tropical CAM-tree Clusia in the field: I. Growth of Clusia rosea Jacq. on St John, US Virgin Islands, Lesser Antilles.

Clusia rosea Jacq. is abundant in the moist parts of the Caribbean island of St John (US Virgin Islands, Lesser Antilles) but relatively rare along the dry south coast. Three types of seedlings were encountered, terrestrial seedlings, seedlings growing as humus-epiphytes on other trees, and seedlings growing inside the tanks of the bromeliad Aechmea lingulata (L.) Baker. Free-living trees grow from terrestrial seedlings or from epiphytic seedlings strangling and shading their host trees. Leaf-Na+ levels were always low (1-4 mequiv I-1 tissue water); trees close to the shore were not affected by salinity. In leaves of mature C. rosea trees, levels of Ca2+ , Mg2+ and K+ were about 60-90, 40-50, 45-55 mequiv I-1 tissue water, respectively. Epiphytic seedlings tended to contain lower levels of these inorganic cations than seedlings growing terrestrially or in the tanks of Ae. lingulata. Epiphytic seedlings contained significantly less nitrogen than terrestrial seedlings. In the leaves of mature trees N-levels were independent of altitude and location on the island, but shaded leaves had significantly higher N-levels than exposed leaves. Light compensation point of photosynthesis in epiphytic seedlings performing C3 -photosynthesis was 17-5 (µmol photons m-2 s-1 ), photosynthesis was saturated at about 300µmol photons m-2 s-1 showing a maximum rate of CO2 -uptake of 2-3 µmol m-2 s-1 .

Kinetic Properties of Phosphoenolpyruvate Carboxylase in Peperomia camptotricha.

Kinetic characteristics of phosphoenolpyruvate carboxylase (PEPC) from the epiphytic C(3) or C(4): CAM intermediate plant, Peperomia camptotricha, were investigated. Few day versus night differences in V(max),K(m(PEP))), or malate inhibition were observed, even in extracts from water-stressed plants which characteristically perform CAM, regardless of efforts to stabilize day/night forms. The PEPC extracted from plants during the light period remained stable, without much of an increase or decrease in activity for at least 22 hours at 0 to 4 degrees C. Extracts from mature, fully developed leaves had slightly greater PEPC activity than from very young, developing leaves. Generally, however, the kinetic properties of PEPC extracted from mature leaves of plants grown under short day (SD), long day (LD), or 1-week water-stress conditions, as well as from young, developing leaves, were similar. The PEPC inhibitor, l-malate, decreased the V(max) and increased the K(m(PEP)) for all treatments. Under specific conditions, malate did not inhibit PEPC rates in the dark extracts as much as the light. The PEPC activator, glucose-6-phosphate (G-6-P), lowered the K(m(PEP)) for all treatments. At saturating PEP concentrations, PEPC activity was independent of pH in the range of 7.5 to 9.0. At subsaturating PEP concentrations, the pH optimum was 7.8. The rates of PEPC activity were lower in the light period extracts than the dark, at pH 7.1, but day/night PEPC was equally active at pH 7.8. At pH 7.5 and a subsaturating PEP concentration, G-6-P significantly activated PEPC. At pH 8, however, only slight activation by G-6-P was observed. The lower pH of 7.5 combined with l-malate addition, greatly inhibited PEPC, particularly in extracts from young, developing leaves which were completely inhibited at an l-malate concentration of 1 millimolar. However, malate did not further inhibit PEPC activity in mature leaves when assayed at pH 7.1. The fairly constant day/night kinetic and regulatory properties of PEPC from P. camptotricha are unlike those of PEPC from CAM or C(4) species studied, and are consistent with the photosynthetic metabolism of this plant.

Effects of Various Levels of CO(2) on the Induction of Crassulacean Acid Metabolism in Portulacaria afra (L.) Jacq.

In response to water stress, Portulacaria afra (L.) Jacq. (Portulacaceae) shifts its photosynthetic carbon metabolism from the Calvin-Benson cycle for CO(2) fixation (C(3)) photosynthesis or Crassulacean acid metabolism (CAM)-cycling, during which organic acids fluctuate with a C(3)-type of gas exchange, to CAM. During the CAM induction, various attributes of CAM appear, such as stomatal closure during the day, increase in diurnal fluctuation of organic acids, and an increase in phosphoenolpyruvate carboxylase activity. It was hypothesized that stomatal closure due to water stress may induce changes in internal CO(2) concentration and that these changes in CO(2) could be a factor in CAM induction. Experiments were conducted to test this hypothesis. Well-watered plants and plants from which water was withheld starting at the beginning of the experiment were subjected to low (40 ppm), normal (ca. 330 ppm), and high (950 ppm) CO(2) during the day with normal concentrations of CO(2) during the night for 16 days. In water-stressed and in well-watered plants, CAM induction as ascertained by fluctuation of total titratable acidity, fluctuation of malic acid, stomatal conductance, CO(2) uptake, and phosphoenolpyruvate carboxylase activity, remained unaffected by low, normal, or high CO(2) treatments. In well-watered plants, however, both low and high ambient concentrations of CO(2) tended to reduce organic acid concentrations, low concentrations of CO(2) reducing the organic acids more than high CO(2). It was concluded that exposing the plants to the CO(2) concentrations mentioned had no effect on inducing or reducing the induction of CAM and that the effect of water stress on CAM induction is probably mediated by its effects on biochemical components of leaf metabolism.

Physiological Changes in Portulacaria afra (L.) Jacq. during a Summer Drought and Rewatering.

The changes of titratable acidity, enzyme activity, water status, and pigment composition were studied in Portulacaria afra (L.) Jacq. during a normal summer drought and rewatering. Two groups of plants were grown outside under a clear plastic canopy with water stress initiated at 2-week intervals in May 1986. Drought resulted in a linear decrease of fresh weight for 80 days and there was no further fresh weight change for the next 65 days. Nocturnal CO(2) uptake remained measurable for 83 days. Cessation of exogenous CO(2) uptake corresponded to the point where the pressure potential (Psi(p)) became zero. Ribulose-1, 5-bisphosphate (RuBP) and phosphoenolpyruvate carboxylase were reduced to 50% of this activity by the end of the drought period. Phosphoenolpyruvate carboxykinase activity was undetectable after 120 to 140 days of drought. Chlorophyll (Chl) levels decreased with a preferential loss of Chl a over Chl b. Carotenoid content was relatively constant over the course of the drought period. After 145 days of drought, plants responded to rewatering within 24 hours; Psi(p) became positive and daytime CO(2) uptake resumed after 24 hours. After 3 days, RuBP carboxylase activity reached control levels. Activity of the CAM pathway recovered after 5 days, as noted by increased diurnal acid fluctuations. Phosphoenolpyruvate carboxylase and phosphoenolpyruvate carboxykinase activity fully recovered within 6 days. Chl levels were greater than control levels within 5 days. Chl a/b ratios took 27 days to return to control levels. The results indicated that P. afra can withstand a normal summer drought by utilizing the CAM and CAM-idling pathway for 130 to 140 days. The plants respond rapidly to rewatering because of the conservation of enzyme activity and the quick recovery of Psi(p).

Carbon Flow and Metabolic Specialization in the Tissue Layers of the Crassulacean Acid Metabolism Plant, Peperomia camptotricha.

Leaves of Peperomia camptotricha contain three distinct upper tissue layers and a one-cell thick lower epidermis. Light and dark CO(2) fixation rates and the activity of ribulose bisphosphate carboxylase/oxygenase and several C(4) enzymes were determined in the three distinct tissue layers. The majority of the C(4) enzyme activity and dark CO(2) fixation was associated with the spongy mesophyll, including the lower epidermis; and the least activity was found in the median palisade mesophyll. In contrast, the majority of the C(3) activity, that is ribulose bisphosphate carboxylase/oxygenase and light CO(2) fixation, was located in the palisade mesophyll. In addition, the diurnal flux in titratable acidity was greatest in the spongy mesophyll and lowest in the palisade mesophyll. The spatial separation of the C(3) and C(4) phases of carbon fixation in P. camptotricha suggests that this Crassulacean acid metabolism plant may have low photorespiratory rates when it exhibits daytime gas exchange (that is, when it is well watered). The results also indicate that this plant may be on an evolutionary path between a true Crassulacean acid metabolism plant and a true C(4) plant.

Relationship between Respiration and CAM-Cycling in Peperomia camptotricha.

Mature leaves of well-watered Peperomia camptotricha show Crassulacean acid metabolism (CAM). Young leaves show CAM-cycling in which CO(2) uptake occurs during the day concomitant with a marked diurnal fluctuation of organic acids as in CAM. Evidence is presented suggesting that respiration is the source of CO(2) for nocturnal acid synthesis in leaves exhibiting CAM-cycling. Respiratory quotients for these leaves were consistently much less than unity despite the fact that the leaves metabolize starch. The conservation of CO(2) by refixation into acids at night represents about 17% of the total photosynthetically fixed CO(2) and about 50% of the total respiratory CO(2).

Developmental Control of CAM in Peperomia scandens.

Experiments were conducted to examine the development of photosynthetic carbon metabolism in Peperomia scandens, a tropical epiphyte. Leaves were sampled during a 10-day period when they were between 30 to 165 days old. P. scandens exhibits a C(3) to CAM-cycling to CAM shift during maturation with the magnitude of CAM increasing with age. Initially, during both day and night, no significant CO(2) uptake or diurnal acid flux was evident. C(3) gas exchange was detected at 41 days of age with a gradual shift towards CAM gas exchange maximized thereafter. An acidity flux of 130 to 150 microequivalents per gram fresh weight was evident by 41 days. Between 40 and 90 days, the leaves shifted their CO(2) uptake pattern from a daytime to a nighttime peak. After 90 days, the leaves remained in CAM. The delta(13)C values became progressively less negative as the leaves matured. In the 30-day-old leaves, the delta(13)C value was -21.1% while in the 165-day-old leaves the delta(13)C value was -18.3%. The time-dependent shift from C(3) to CAM-cycling to CAM in P. scandens does not appear to result from changes in water, light, or temperature regimes since these variables were constant for all leaves sampled.

Minor Physiological Response to Elevated CO(2) by the CAM Plant Agave vilmoriniana.

One-year-old plants of the CAM leaf succulent Agave vilmoriniana Berger were grown outdoors at Riverside, California. Potted plants were acclimated to CO(2)-enrichment (about 750 microliters per liter) by growth for 2 weeks in an open-top polyethylene chamber. Control plants were grown nearby where the ambient CO(2) concentration was about 370 microliters per liter. When the plants were well watered, CO(2)-induced differences in stomatal conductances and CO(2) assimilation rates over the entire 24-hour period were not large. There was a large nocturnal acidification in both CO(2) treatments and insignificant differences in leaf chlorophyll content. Well watered plants maintained water potentials of -0.3 to -0.4 megapascals. When other plants were allowed to dry to water potentials of -1.2 to -1.7 megapascals, stomatal conductances and CO(2) uptake rates were reduced in magnitude, with the biggest difference in Phase IV photosynthesis. The minor nocturnal response to CO(2) by this species is interpreted to indicate saturated, or nearly saturated, phosphoenolpyruvate carboxylase activity at current atmospheric CO(2) concentrations. CO(2)-enhanced diurnal activity of ribulose bisphosphate carboxylase activity remains a possibility.

Photosynthesis in epiphytic and rooted Clusia rosea Jacq.

Clusia rosea Jacq. is a hemiepiphyte having Crassulacean Acid Metabolism (CAM). In its natural habitat Clusia begins its life cycle as an epiphyte and eventually becomes a rooted tree. These two stages of the life cycle of Clusia represent markedly different water regimes. Our CO2 exchange, stomatal conductance, titratable acidity, and stable carbon isotope ratio measurements indicate that Clusia has a flexible photosynthetic mode, where CO2 is fixed mostly via CAM during its epiphytic stage, when water availability is low, and via both CAM and C3 during its rooted stage.

Phosotynthesis in hemiepiphytic species of Clusia and Ficus.

Hemiepiphytic species in the genera Clusia and Ficus were investigated to study their mode of photosynthetic metabolism when growing under natural conditions. Despite growing sympatrically in many areas and having the same growth habit, some Clusia species show Crassulacean acid metabolism (CAM) whereas all species of Ficus investigated are C3. This conclusion is based on diurnal CO2 fixation patterns, diurnal stomatal conductances, diurnal titratable acidity fluctuations, and δ13C isotope ratios. Clusia minor, growing in the savannas adjacent to Barinas, Venezuela, shows all aspects of Crassulacean acid metabolism (CAM) on the basis of nocturnal gas exchange, stomatal conductance, total titratable acidity, and carbon isotope composition when measured during the dry season (February 1986). During the wet season (June 1986), the plants shifted to C3-type gas exchange with all CO2 uptake occurring during the daylight hours. The carbon isotope composition of new growth was-28 to-29‰ typical of C3 plants.

Crassulacean Acid Metabolism in the Strangler Clusia rosea Jacq.

Observations of malic acid fluctuation, leaf anatomy, and stable carbon isotopic composition showed that the epiphytic strangler Clusia rosea, growing on Saint John, U.S. Virgin Islands, has crassulacean acid metabolism. This hemiepiphyte may be the only woody dicotyledonous tree species among the many thousands of flowering species in the 30 or more plant families that shows this type of metabolism. The finding has implications with respect to water balance during the process whereby Clusia rosea establishes itself as a tree, since crassulacean acid metabolism is a photosynthetic adaptation to water-stressed environments.

Physiological and isotopic aspects of photosynthesis in peperomia.

Physiological and isotopic aspects of several Peperomia species were investigated. All but one species had C(3)-like stomatal behavior, in that stomata were open during the day and closed during the night. In these species, most atmospheric CO(2) uptake occurred during the day. Concurrent with this stomatal behavior, there were Crassulacean acid metabolism-like acid fluctuations in most species. Carbon and hydrogen isotope ratios of cellulose nitrate from Peperomia reflect their physiological behavior. The delta(13)C values of cellulose nitrate from Peperomia species were similar to values observed in C(3) plants and consistent with the daytime uptake of exogeneous CO(2) via the C(3) photosynthetic pathway. The deltaD values of cellulose nitrate from Peperomia species approach those of Crassulacean acid metabolism plants. These elevated deltaD values are caused by fractionations occurring during biochemical reactions and not as a consequence of water relations.

Crassulacean Acid Metabolism and Crassulacean Acid Metabolism Modifications in Peperomia camptotricha.

Peperomia camptotricha, a tropical epiphyte from Mexico, shows variable forms of Crassulacean acid metabolism (CAM). Young leaves exhibit CAM-cycling, while mature leaves show an intermediate type of metabolism, between CAM and CAM-cycling, having approximately the same amount of nighttime gas exchange as daytime. Metabolism of young leaves appears independent of daylength, but mature leaves have a tendency toward more CAM-like metabolism under short days (8 hours). Large differences in the physical appearance of plants were found between those grown under short daylengths and those grown under long daylengths (14 hours). Some anatomical differences were also detected in the leaves. Water stress caused a switch to CAM in young and mature leaves, and as water stress increased, they shifted to CAM-idling.

Carbon, hydrogen, and oxygen isotope ratios of cellulose from plants having intermediary photosynthetic modes.

Carbon and hydrogen isotope ratios of cellulose nitrate and oxygen isotope ratios of cellulose from species of greenhouse plants having different photosynthetic modes were determined. When hydrogen isotope ratios are plotted against carbon isotope ratios, four clusters of points are discernible, each representing different photosynthetic modes: C(3) plants, C(4) plants, CAM plants, and C(3) plants that can shift to CAM or show the phenomenon referred to as CAM-cycling. The combination of oxygen and carbon isotope ratios does not distinguish among the different photosynthetic modes. Analysis of the carbon and hydrogen isotope ratios of cellulose nitrate should prove useful for screening different photosynthetic modes in field specimens that grew near one another. This method will be particularly useful for detection of plants which show CAM-cycling.

Shifts in the Carbon Metabolism of Xerosicyos danguyi H. Humb. (Cucurbitaceae) Brought About by Water Stress : I. General Characteristics.

Xerosicyos danguyi H. Humb. (Cucurbitaceae) is an unusual leaf succulent endemic to Madagascar. Under well-watered conditions the plant exhibited Crassulacean acid metabolism (CAM), as characterized by large diurnal changes in titratable acidity, predominantly nighttime stomatal opening and CO(2) uptake, and high delta(13)C values. When plants were exposed to water stress for a minimum of a month, they shifted to a mode of carbon metabolism previously labeled CAM-idling. Under this mode of metabolism, the plants exhibited reduced stomatal opening, reduced CO(2) uptake, dampened diurnal fluctuations in titratable acidity, and no apparent changes in the delta(13)C values. Additionally, investigations showed that the stress hormones 1-aminocyclopropane-1-carboxylic acid (an ethylene precursor) and abscisic acid increased as much as 6-fold in the water-stressed plants. The results are discussed in relation to physiological significance and evolution of the CAM-idling mode of metabolism.