Microclimate reveals the true thermal niche of forest plant species

Species distributions are conventionally modelled using coarse-grained macroclimate data measured in open areas, potentially leading to biased predictions since most terrestrial species reside in the shade of trees. For forest plant species across Europe, we compared conventional macroclimate-based species distribution models (SDMs) with models corrected for forest microclimate buffering. We show that microclimate-based SDMs at high spatial resolution outperformed models using macroclimate and microclimate data at coarser resolution. Additionally, macroclimate-based models introduced a systematic bias in modelled species response curves, which could result in erroneous range shift predictions. Critically important for conservation science, these models were unable to identify warm and cold refugia at the range edges of species distributions. Our study emphasizes the crucial role of microclimate data when SDMs are used to gain insights into biodiversity conservation in the face of climate change, particularly given the growing policy and management focus on the conservation of refugia worldwide.

ForestClim-Bioclimatic variables for microclimate temperatures of European forests

Microclimate research gained renewed interest over the last decade and its importance for many ecological processes is increasingly being recognized. Consequently, the call for high-resolution microclimatic temperature grids across broad spatial extents is becoming more pressing to improve ecological models. Here, we provide a new set of open-access bioclimatic variables for microclimate temperatures of European forests at 25 × 25 m² resolution.

Can high-resolution topography and forest canopy structure substitute microclimate measurements? Bryophytes say no

Increasingly available high-resolution digital elevation models (DEMs) facilitate the use of fine-scale topographic variables as proxies for microclimatic effects not captured by the coarse-grained macroclimate datasets. Species distributions and community assembly rules are, however directly shaped by microclimate and not by topography. DEM-derived topography, sometimes combined with vegetation structure, is thus widely used as a proxy for microclimatic effects in ecological research and conservation applications. However, the suitability of such a strategy has not been evaluated against in situ measured microclimate and species composition. Because bryophytes are highly sensitive to microclimate, they are ideal model organisms for such evaluation. To provide this much needed evaluation, we simultaneously recorded bryophyte species composition, microclimate, and forest vegetation structure at 218 sampling sites distributed across topographically complex sandstone landscape. Using a LiDAR-based DEM with a 1 m resolution, we calculated eleven topographic variables serving as a topographic proxy for microclimate. To characterize vegetation structure, we used hemispherical photographs and LiDAR canopy height models. Finally, we calculated eleven microclimatic variables from a continuous two-year time- series of air and soil temperature and soil moisture. To evaluate topography and vegetation structure as substitutes for the ecological effect of measured microclimate, we partitioned the variation in bryophyte species composition and richness explained by microclimate, topography, and vegetation structure. In situ measured microclimate was clearly the most important driver of bryophyte assemblages in temperate coniferous forests. The most bryophyte-relevant variables were growing degree days, maximum air temperature, and mean soil moisture. Our results thus showed that topographic variables, even when derived from high-resolution LiDAR data and combined with in situ sampled vegetation structure, cannot fully substitute effects of in situ measured microclimate on forest bryophytes.

Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications.

Atraumatic acute compartment syndrome - case report

INTRODUCTION

The publishing of our case report on an idiopathic compartment syndrome of both upper limbs after icing a contusion trauma was motivated by another article on the acute spontaneous compartment syndrome of upper limb published in Rozhledy v chirurgii 8/2021.

CASE REPORT

We present the case of a 43-year-old man admitted in the evening for painful massive swelling of both upper extremities. The swelling developed immediately after icing his bruises suffered due to a probable fall on the previous day in a state of inebriety. Compartment syndrome of the left hand and right forearm was diagnosed; subsequently, adequate dermatofasciectomy resulted in normalization of the condition in both upper limbs. The patients condition was cured to a full extent without any disorders of perfusion, mobility or sensation in both upper extremities.

CONCLUSION

Only few reports on the atraumatic compartment syndrome of upper extremity can be found in the literature and it is an acute condition encountered quite rarely at outpatient offices of surgery. Nevertheless, we need to be able to recognize this nosological unit and provide proper treatment in time, otherwise the patient may suffer serious permanent damage.

ForestTemp - Sub-canopy microclimate temperatures of European forests

Ecological research heavily relies on coarse-gridded climate data based on standardized temperature measurements recorded at 2 m height in open landscapes. However, many organisms experience environmental conditions that differ substantially from those captured by these macroclimatic (i.e. free air) temperature grids. In forests, the tree canopy functions as a thermal insulator and buffers sub-canopy microclimatic conditions, thereby affecting biological and ecological processes. To improve the assessment of climatic conditions and climate-change-related impacts on forest-floor biodiversity and functioning, high-resolution temperature grids reflecting forest microclimates are thus urgently needed. Combining more than 1200 time series of in situ near-surface forest temperature with topographical, biological and macroclimatic variables in a machine learning model, we predicted the mean monthly offset between sub-canopy temperature at 15 cm above the surface and free-air temperature over the period 2000-2020 at a spatial resolution of 25 m across Europe. This offset was used to evaluate the difference between microclimate and macroclimate across space and seasons and finally enabled us to calculate mean annual and monthly temperatures for European forest understories. We found that sub-canopy air temperatures differ substantially from free-air temperatures, being on average 2.1°C (standard deviation ± 1.6°C) lower in summer and 2.0°C higher (±0.7°C) in winter across Europe. Additionally, our high-resolution maps expose considerable microclimatic variation within landscapes, not captured by the gridded macroclimatic products. The provided forest sub-canopy temperature maps will enable future research to model below-canopy biological processes and patterns, as well as species distributions more accurately.

SoilTemp: A global database of near-surface temperature

Current analyses and predictions of spatially explicit patterns and processes in ecology most often rely on climate data interpolated from standardized weather stations. This interpolated climate data represents long-term average thermal conditions at coarse spatial resolutions only. Hence, many climate-forcing factors that operate at fine spatiotemporal resolutions are overlooked. This is particularly important in relation to effects of observation height (e.g. vegetation, snow and soil characteristics) and in habitats varying in their exposure to radiation, moisture and wind (e.g. topography, radiative forcing or cold-air pooling). Since organisms living close to the ground relate more strongly to these microclimatic conditions than to free-air temperatures, microclimatic ground and near-surface data are needed to provide realistic forecasts of the fate of such organisms under anthropogenic climate change, as well as of the functioning of the ecosystems they live in. To fill this critical gap, we highlight a call for temperature time series submissions to SoilTemp, a geospatial database initiative compiling soil and near-surface temperature data from all over the world. Currently, this database contains time series from 7,538 temperature sensors from 51 countries across all key biomes. The database will pave the way toward an improved global understanding of microclimate and bridge the gap between the available climate data and the climate at fine spatiotemporal resolutions relevant to most organisms and ecosystem processes.

Secondary appendicitis in an adult patient with an ascended testicle - case report

Acute appendicitis is one of the most common acute abdomen cases. Although many causes have been described in literature, it is mostly primary affection of the appendix that leads to acute appendicitis. A 57-year-old patient was admitted to our department displaying all usual signs of acute appendicitis, both clinical and laboratory. During laparoscopic appendectomy, we found the inflammation of the appendix in this case appeared secondary, originating in a structure located nearby the appendix, strongly resembling a testicle. We performed appendectomy and removed the suspected structure altogether. The patient recovered completely within a week. Subsequent histological examination confirmed that the suspected tissue was indeed a retained testicle causing se-condary inflammation of the appendix. As we found out later, this condition probably occurred in the patient secondarily in adulthood, most likely due to inguinal hernia repair undergone during childhood.

A meta-analysis of global fungal distribution reveals climate-driven patterns

The evolutionary and environmental factors that shape fungal biogeography are incompletely understood. Here, we assemble a large dataset consisting of previously generated mycobiome data linked to specific geographical locations across the world. We use this dataset to describe the distribution of fungal taxa and to look for correlations with different environmental factors such as climate, soil and vegetation variables. Our meta-study identifies climate as an important driver of different aspects of fungal biogeography, including the global distribution of common fungi as well as the composition and diversity of fungal communities. In our analysis, fungal diversity is concentrated at high latitudes, in contrast with the opposite pattern previously shown for plants and other organisms. Mycorrhizal fungi appear to have narrower climatic tolerances than pathogenic fungi. We speculate that climate change could affect ecosystem functioning because of the narrow climatic tolerances of key fungal taxa.

The authors assemble and analyse previously generated mycobiome data linked to geographical locations across the world. They describe the distribution of fungal taxa and show that climate is an important driver of fungal biogeography and that fungal diversity appears to be concentrated at high latitudes.

Correlations between intratumoral vascular network and tumoral architecture in prostatic adenocarcinoma

The authors made a preliminary assessment of possible correlations between the intratumoral vascular density (IVD) and the architectural tumoral patterns described by Gleason. The studied material consisted of samples obtained by transurethral resection from 34 patients diagnosed with prostatic adenocarcinoma. Ten fields, five for dominant and five for secondary identified patterns of each case, with no necrosis were selected randomly from CD34 immunomarked sections using ×20 objective. IVD increased with Gleason pattern both for the entire group, but also for "solid" phenotype group of subtypes up to pattern 4, respectively subtype 4B. In "necrotizing" phenotype group of subtypes, IVD had a decreasing trend from the better-differentiated subtypes to the poorest one. These preliminary data showed that the intratumoral vascular network reacts differently to the loss of tumoral differentiation in the two groups of Gleason subtypes suggesting the existence of two different populations of malignant cells.

Correlations between intratumoral interstitial fibrillary network and tumoral architecture in prostatic adenocarcinoma

The authors made a preliminary assessment of possible correlations between the amount of intratumoral stromal fibrillary components (ISFC) and the architectural tumoral patterns described by Gleason. The studied material consisted of samples obtained by transurethral resection from 34 patients diagnosed with prostatic adenocarcinoma. Ten fields, five for dominant and five for secondary identified patterns of each case, with no necrosis were selected randomly from Gömöri stained sections using ×20 objective. ISFC-ratio increased with Gleason pattern both for the entire group but also for "Necrotizing" phenotype patterns and "Solid" phenotype patterns, excepting the subtype "4A" where the stromal compartment was reduced by the expansion of tumoral ducts enlarged by growing tumoral intraductal cribriform masses. These preliminary data showed that stromal microenvironment try to adapt to the loss of tumoral differentiation by increasing the amount of fibrillary components of intratumoral stromal compartment.

Clinical significance of the plasminogen activator system in relation to grade of tumor and treatment response in colorectal carcinoma patients

Urokinase (uPA) plays an essential role in the activation of plasminogen to plasmin, and together with its receptor (uPAR), tissue activator (tPA) and urokinase inhibitors (PAI 1, PAI 2, PAI 3 and protease nexin) forms the plasminogen activator system (PAS), a component of metastatic cascade importantly contributing to the invasive growth and angiogenesis of malignant tumours. In our project we examined the expression of uPA, uPAR, PAI 1 and PAI 2 in tumor tissue and we also studied the plasma levels of PAI 1 before and after the initiation of therapy in patients with colorectal carcinoma in relationship to grade of tumor and the treatment response. In our prospective evaluation we included 80 patients treated for adenocarcinoma of the colon and rectum. Analysis of collected data revealed statistically significant evidence of a relationship between the level of PAI 1 in plasma before treatment and grade of the tumor, which increases with tumor grade (p=0.025). We demonstrated that there exists a statistically significant relationship between the expression of PAI 2 (p<0.001) and uPAR (p=0.031) and grade of tumor. We also confirmed a statistically significant relationship between soluble levels of PAI 1 before treatment and therapeutic response (p=0.021). In our group of patients the expression of uPA, uPAR, PAI 1 and 2 in tumor tissue in relation to response to treatment was also assessed. Our results suggest that the greater expression of these parameters in tumor tissue is linked to a worse response to therapy. In conclusion, PAS factors help as a prognostic indicators and could also act as a predictive factor in colorectal carcinoma.

[Radiofrequency ablation of pancreatic neuroendocrine tumor]

BACKGROUNDS

Pancreatic neuroendocrine tumors (PNETs) include a broad range of neoplasms spanning from relatively benign to malignant. Radical resection has been advocated as the only curative method. Debulking (R2) resection can be indicated for locally unresectable PNETs. Debulking surgery improves the quality of life and prolongs overall survival. The disadvantages of this approach include bleeding, pancreatic fistula and tumor spread. No alternative method that would eliminate these complications has been published yet. Considering the encouraging results of the studies describing radiofrequency ablation (RFA) of locally advanced pancreatic cancer, a question arises, whether it might be possible to use RFA as a R2 resection alternative in PNETs.

CASE

A 73-year-old gentleman had been admitted due to abdominal pain and hyperglycaemic syndrome. Contrast-enhanced CT showed a tumor of pancreatic head invading portal vein (PV) and superior mesenteric vein (VMS). A surgery was indicated on the basis of EUS-guided FNAB that verified a PNET of uncertain biological behaviour. The surgery confirmed a locally advanced tumor of pancreatic head invading the PV and SMV. Due to the polymorbidity, radical pancreatoduodenectomy with SMV resection was not indicated. Because of the presence of symptoms, RFA of the PNET using ValleyLab generator with cooltip cluster electrode, was performed. Postoperative course was uneventful. Final immunohistochemical examination verified a well-differentiated grade 1 PNET. The patient was regularly monitored during a three-year follow-up. The quality of life was evaluated using standardized EORT QLQ-30 questionnaire. Pain was assessed by a ten-point visual analogue scale (VAS). Ablated area was evaluated annually by contrast-enhanced CT. Postoperatively, abdominal pain ceased (pain decrease from 2 to 0 on VAS). Insulin dose was reduced from 46 IU (international units) to 20 IU of Humulin-R per day. CT verified tumor regression according to RECIST (response evaluation criteria in solid tumors). During the three-year follow-up, no local progression or tumor dissemination was observed.

CONCLUSION

We present the first case report of a patient with locally advanced symptomatic pancreatic neuroendocrine tumor successfully treated by intraoperative radiofrequency ablation. More clinical studies are needed to evaluate the clinical relevance of this cytoreductive method in the PNET indication.

[Outcomes of pancreatic resections in the elderly and geriatric patients]

As a result of the population aging, we are confronted with the problematics of geriatric patients more and more frequently. The aim of this retrospective study was to compare outcomes of pancreatic resections in patients of three different age groups. During 2000-2007, 150 pancreatic resections were performed in our clinic, including 34 (22.7%) patients aged 65 and over at the time of the procedure and 5 (3.3%) patients over 75 y.o.a. The procedures were heterogenous, including indications for oncologic diagnoses, as well as for chronic pancreatitis. Our assessment demonstrated no significant differences in the 30-day postoperative mortality between the group of subjects over 65 y.o.a, geriatric group (i.e. over 75 y.o.a) and the group of subjects below 54 y.o.a. (8.8% vs. 0% vs. 5.2%). Furthermore, the postoperative morbidity showed no statistically significant differences between the all three groups (30.2% vs. 29.4% vs. 20%). The commonest postoperative complications included secondary healing of the surgical wound (7.8%) and pancreatic fistules (6.9%) in the group of subjects below 65 y.o.a., and insufficiency of the pancreatic-jejunal anastomosis (5.8%) and hepatic- jejunal anastomosis (5.88%) in the group aged 65 and over. Pancreatic-jejunal anastomosis insufficiency, complicated by consecutive bleeding, contributed to postoperative mortality most significantly. Significant increase in postoperative complication rates connected to proximal pancreatoduodenectomies and total pancreatoduodenectomies, was recorded in patients over 65, compared to those in the young patient group (p = 0.014). No statistically significant relation was found between a particular comorbidity and onset of postoperative complications or deaths in patients over 65 or geriatric patients. Based on the results, the authors do not consider the patient's age a contraindication for pancreatic resection procedures. Radical resections can be performed with acceptable mortality and morbidity rates in geriatric patients.

[Radiofrequency ablation (RFA) of pancreatic tumors]

The authors refer about their first experience with radiofrequency ablation of locally advanced pancreatic tumors. They put forward the prospective study of five patients (four with ductal adenocarcinoma of the head and one with malignant neuroendocrine tumor of pancreatic body), who either because of local advanced disease or performance status, were not able to undergo radical curative surgery. All patients underwent peroperative radiofrequency ablation of pancreatic tumors. In the case of pancreatic head localization, posterior retrocolic gastro-enterostomy and hepatico-jejunostomy to Y Roux jejunal loop were performed. There was no perioperative mortality. In one case duodenal leak apeared in the fourth postoperative day. This was healed conservatively by drainage. At one patient the subfascial absces developed. This was solved by drainage reoperation at the fourteenth postoperative day. After consolidation, all patients were released to home care.

CONCLUSION

According to our early experience, radiofrequency ablation of inoperable pancreatic tumors is relatively save cytoreductive procedure.

[Krukenberg tumors of gastric origin versus Krukenberg tumors of colorectal origin]

The aim of this study was to analyze the incidence and origin of Krukenberg tumors in our region to determine their clinical behavior and to compare some anatomo-clinical features of Krukenberg tumors of gastric origin versus those of colorectal origin. This is a retrospective, descriptive and comparative study of Krukenberg tumors diagnosed and treated in the IV-th Surgical Clinic of Cluj-Napoca. The epidemiologic features concerning global incidence, age, and menopausal status overlap the data from literature. Characteristic for our series of cases were the higher incidence of Krukenberg tumor of colorectal origin compared with those of gastric origin , significantly more frequent bilaterality of lesions of gastric origin and the prevalence of the unilateral left ovarian localization for Krukenberg tumors of colorectal origin. The differences in anatomo-clinical behavior between the Krukenberg tumors of gastric and colorectal origin may indicate different pathways of metastasizing and seeding.

An association study of 43 SNPs in 16 candidate genes with atorvastatin response

Variation in individual response to statin therapy has been widely studied for a potential genetic component. Multiple genes have been identified as potential modulators of statin response, but few study findings have replicated. To further examine these associations, 2735 individuals on statin therapy, half on atorvastatin and the other half divided among fluvastatin, lovastatin, pravastatin and simvastatin were genotyped for 43 SNPs in 16 genes that have been implicated in statin response. Associations with low-density lipoprotein cholesterol (LDL-C) lowering, total cholesterol lowering, HDL-C elevation and triglyceride lowering were examined. The only significant associations with LDL-C lowering were found with apoE2 in which carriers of the rare allele who took atorvastatin lowered their LDL-C by 3.5% more than those homozygous for the common allele and with rs2032582 (S893A in ABCB1) in which the two groups of homozygotes differed by 3% in LDL-C lowering. These genetic effects were smaller than those observed with the demographic variables of age and gender. The magnitude of all the differences found is sufficiently small that genetic data from these genes should not influence clinical decisions on statin administration.

Brown tumor of the spine and progressive paraplegia in a hemodialysis patient

STUDY DESIGN

Case report.

OBJECTIVE

To describe the radiographic features and management of spinal brown tumor and to document tumor mineralization after parathyroidectomy.

SUMMARY OF BACKGROUND DATA

Brown tumors are classic skeletal manifestations of hyperparathyroidism usually seen in severe forms. They are increasingly rare because hyperparathyroidism is now diagnosed and treated at an early stage.

METHODS

A case of brown tumor of the spine in a 37-year-old woman on chronic hemodialysis is described. The imaging findings before and after parathyroidectomy are discussed.

RESULTS

In a woman on chronic hemodialysis, a brown tumor of T8 caused acute spinal cord compression with paraplegia. Magnetic resonance imaging provided an accurate evaluation of the lesion, and needle biopsy confirmed the diagnosis. Emergent surgery was needed to relieve the spinal compression and stabilize the spine. The vertebral lesion underwent remineralization after parathyroidectomy.

CONCLUSION

Brown tumor is a benign tumor that resolves after parathyroidectomy. When brown tumor arises in the spine, surgery may be needed to preserve neurologic function.

[Role of mini-invasive surgery in the treatment of patients with neoplasms, particularly in colorectal carcinoma]

Laparoscopic surgery has found its firm position in the treatment of benign diseases. Yet, oncologic laparoscopy remains a controversial technique. Its indication is discussed, especially its specific complication in oncologic diseases--recurrence of malign tumors within the scar after the trocar. The authors have performed an extensive recherché on the incidence of local recurrences of malign tumors after laparotomy or laparoscopy. They compare the functional results of both techniques, radical measure of intervention and their technical limits. They analyse the causes of local recurrences as well as possibilities of their reduction. They evaluate also their own experience in laparoscopy performed in coincidence with malign diseases, especially in palliative surgery. They suggest indications of laparoscopy in cases with colorectal carcinoma which is currently, as well as prospectively the most frequent malign disease of the gastrointestinal tract in our region.

[Gastroesophageal reflux disease from the viewpoint of the surgeon]

Surgical treatment of patients with gastroesophageal reflux disease (GERD) represents an alternative approach in relation to the long-term pharmacologic therapy of prokinesis, and secretoinhibitory therapy. It must be considered in cases where the conservative approach has failed. The success of surgical treatment depends on an individual approach to the patient. The factors determining the surgical indication and especially the type of surgery, include age, anatomy of the hiatus and the results of pre-operational examinations of the esophagus. The type of operation depends on the ability of the esophagus to contract and to transfer the propulsion activity. According to the authors, the key examination is represented by the detection of esophageal contractility by use of esophageal manometry. The alternative option is represented by scintigraphic measurement of esophageal transit time by use of a tagged bolus. The patients with disappeared contractility are preferentially treated by conservative therapy due to the high risk of post-operational dysphagia. 80% of patients are treated by the standard procedure of laparoscopic fundoplication by a 360-grade cuff. The cases with decreased contractility or esophageal dysmotility are preferentially treated by partial fundoplication in Toupet's modification. The shortening of the esophagus requires consideration as to chest approach, or Collis' operation. Intestinal metaplasia of the esophagus requires specific procedures. Severe dysplastic changes require the consideration of resection treatment. The gained therapeutic results are evaluated by both, the subjective point of view of the authors, as well as by standard pH measurement and manometry of the esophagus performed 6 weeks after surgery.

Clinicopathological significance of p16 gene expression in the surgical treatment of head and neck squamous cell carcinomas

AIMS

To evaluate the clinicopathological significance of p16 expression in the surgical management of squamous cell carcinomas of the oral cavity, oropharynx, hypopharynx, and larynx.

METHOD

p16 expression in 225 head and neck squamous cell carcinomas (HNSCCs) was studied using an immunohistochemical method and paraffin wax embedded tumour tissues. Associations between p16 expression and clinicopathological features were investigated.

RESULTS

Decreased p16 expression was found in 48% of the tumours. There was a higher frequency of decreased p16 expression in tumours of the larynx compared with those from the pharynx and oral cavity. There was a significant correlation between decreased p16 expression and more advanced T stage. There was no significant correlation between p16 expression and sex, age, tumour grade, nodal metastasis, recurrence, or survival.

CONCLUSION

There was a high frequency of downregulation of p16 expression in HNSCC. Tumours of the larynx had a significantly higher frequency of weak p16 expression compared with tumours of the oral cavity and pharynx. Downregulation of p16 contributed to cellular proliferation, resulting locally in a more advanced tumour. It had no prognostic significance for nodal metastasis and survival.

The disposition of saquinavir in normal and P-glycoprotein deficient mice, rats, and in cultured cells

Protease inhibitors are very effective in treating patients infected with HIV. However, many drugs in this class penetrate poorly into the central nervous system (CNS) and may permit this site to be a sanctuary from which resistant virus can emerge. Previous studies have shown that the protease inhibitor saquinavir (SQV) interacts with the multidrug transport system, P-glycoprotein (P-gp), expressed in epithelial cells in the gut mucosa and at the blood-brain barrier, and thus might affect both the oral absorption and the penetration of SQV into the CNS. To determine whether SQV is a substrate for P-gp, its uptake was determined in cancer cells, which do (Dx5) and do not (MES-SA) express P-gp. The distribution of SQV between brain tissue and plasma was also investigated in rats and in normal and P-gp-deficient mdr1a(-/-) mice. The distribution ratio of SQV in plasma:brain:cerebrospinal fluid was approximately 100:10:0.2 in rats. The accumulation of SQV was enhanced in MES-SA cells (P-gp-negative) versus Dx5 cells (P-gp-positive). Bolus i.v. injection of [(14)C]SQV (2 and 5 mg/kg) into mdr1a(-/-) and normal mice (n = 3 or 4) resulted in 3-fold higher radioactivity in brains from mdr1a(-/-) mice. Similarly, oral administration of [(14)C]SQV (500 mg/kg) resulted in a 5-fold increase in systemic exposure and a 10-fold increase in brain levels in mdr1a(-/-) mice. These data demonstrate that saquinavir is a substrate for P-gp and that this transport system may play a role in limiting oral absorption and CNS exposure to this protease inhibitor.

[Breast tuberculosis--a case report]

The authors report a case of breast tuberculosis in a 58-year-old patient in which the diagnosis was made with difficulty, initially the case being interpreted as a neoplastic process. This diagnosis should be considered in such cases. In our area, in the present tuberculosis endemic, the cases of tuberculosis with extrapulmonary localisation are more and more frequent.

[Gangliocytic paraganglioma of the duodenum]

Gangliocytic Paraganglioma of the duodenum is rare neuroendocrine tumor. This type of the tumor can cause bleeding into the gastrointestinal tract and epigastric pain in this region. It can be difficult to differentiate this tumor from the primary tumor of the head of the pancreas growing secondary to the duodenum. The authors describe one such misdiagnosed case treated finally successfully by hemipancreatodecodenectomy.

Acromioclavicular dislocations: treatment by coracoacromial ligamentoplasty

We did a retrospective review of 32 patients who had undergone acute treatment for acromioclavicular joint dislocation (mean follow-up period 46 months) and 24 patients who had undergone surgery for chronic joint dislocation (mean follow-up period 51 months). All patients had a ligamentoplasty performed using the coracoacromial ligament. With the shoulder functional score described by Patte, we obtained 81% satisfactory results for the patients who underwent acute treatment and 79% satisfactory results for those who underwent late treatment. Because results in both groups were similar, we now treat only the more severe form of acute dislocation with surgery. Delayed surgery is indicated in those patients who have an unsatisfactory result after functional treatment.

Entrapment and compartment syndromes of the upper limb in haemophilia

17 patients with haemophilia have been treated for a neurological deficit of the upper limb. Four of the five entrapment neuropathies have been operated upon, and only two patients recovered completely. Only two of the 12 patients with a compartment syndrome have been operated upon, and only two had sequelae. Clotting factor replacement is always indicated as primary treatment. Surgical release is indicated if the condition fails to improve. Late treatment was responsible for incomplete recovery, whatever the cause of the nerve compression.

Isotope dilution technique for the estimation of l-alpha-[2-3H]-acetylmethadol and its metabolites in biological samples

An isotope dilution technique for the determination of l-alpha-(2-3H)-acetylmethadol and its metabolites from biological samples is described. The parent drug and metabolites were extracted from biological samples with chlorobutane after the addition of unlabeled internal standards. The extracts were purified by two-dimensional thin-layer chromatography for quantification by gas-liquid chromatography and scintillation counting. Dinoracetylmethadol (NNAM) was found to be converted to 6-acetamido-4,4-diphenyl-3-heptanol (AMIDE) during the extraction procedure. The conversion of NNAM to AMIDE was confirmed by gas chromatography-mass spectrometry.