Geographical variation in species' population responses to changes in temperature and precipitation

Despite increasing concerns about the vulnerability of species' populations to climate change, there has been little overall synthesis of how individual population responses to variation in climate differ between taxa, with trophic level or geographically. To address this, we extracted data from 132 long-term (greater than or equal to 20 years) studies of population responses to temperature and precipitation covering 236 animal and plant species across terrestrial and freshwater habitats. Our results identify likely geographical differences in the effects of climate change on populations and communities in line with macroecological theory. Temperature tended to have a greater overall impact on populations than precipitation, although the effects of increased precipitation varied strongly with latitude, being most positive at low latitudes. Population responses to increased temperature were generally positive, but did not vary significantly with latitude. Studies reporting significant climatic trends through time tended to show more negative effects of temperature and more positive effects of precipitation upon populations than other studies, indicating climate change has already impacted many populations. Most studies of climate change impacts on biodiversity have focused on temperature and are from middle to high northern latitudes. Our results suggest their findings may be less applicable to low latitudes.

Mechanisms underpinning climatic impacts on natural populations: altered species interactions are more important than direct effects

Shifts in species' distribution and abundance in response to climate change have been well documented, but the underpinning processes are still poorly understood. We present the results of a systematic literature review and meta-analysis investigating the frequency and importance of different mechanisms by which climate has impacted natural populations. Most studies were from temperate latitudes of North America and Europe; almost half investigated bird populations. We found significantly greater support for indirect, biotic mechanisms than direct, abiotic mechanisms as mediators of the impact of climate on populations. In addition, biotic effects tended to have greater support than abiotic factors in studies of species from higher trophic levels. For primary consumers, the impact of climate was equally mediated by biotic and abiotic mechanisms, whereas for higher level consumers the mechanisms were most frequently biotic, such as predation or food availability. Biotic mechanisms were more frequently supported in studies that reported a directional trend in climate than in studies with no such climatic change, although sample sizes for this comparison were small. We call for more mechanistic studies of climate change impacts on populations, particularly in tropical systems.

Molecular characterization of human adenomyosis

Adenomyosis is a common gynaecological disorder characterized by the abnormal growth of endometrium into the myometrium and myometrial hypertrophy/hyperplasia. Uterine fibroids are benign neoplasms of the myometrium, and they represent a diagnostic pitfall for adenomyosis. In this study, we have used the genome-wide Affymetrix U133 Plus 2.0 microarray platform to compare the gene expression patterns of adenomyosis, uterine fibroids, normal endometrium and myometrium. Unsupervised principal component analysis (PCA) revealed that these four tissue types could be segregated from one another solely based on their gene expression profiles. Analysis of variance (ANOVA), followed by Tukey means separation test, significance analysis of microarrays (SAM) and 2-fold change threshold, identified 7415 probe sets as differentially expressed among the four groups of samples. Supervised cluster analysis based on these probe sets clustered adenomyosis most closely with endometrium and uterine fibroids with myometrium, consistent with the anatomic origin of these two diseases. The Tukey means separation post hoc testing found 2073 probe sets altered between adenomyosis and normal endometrium or myometrium, and 2327 probe sets altered in expression when comparing uterine fibroids with myometrium. Using Ingenuity Pathways Analysis (IPA), we found 9 highly significant functional networks in adenomyosis and 10 in uterine fibroids. Notably, the top network in both cases was associated with functions implicated in cancer and cell death. Finally, we compared the gene expression profiles of adenomyosis and uterine fibroids and identified 471 differentially expressed probe sets that may represent potential biomarkers for the differential diagnosis of these diseases.

Chromosome arm 17p deletion analysis reveals molecular genetic heterogeneity in supratentorial and infratentorial primitive neuroectodermal tumors of the central nervous system

The current World Health Organization (WHO) classification groups together both infratentorial neoplasms (medulloblastomas) and their supratentorial counterparts as primitive neuroectodermal tumors (PNETs), implying a common origin. Previous analyses of medulloblastoma have shown loss of chromosome arm 17p as the most frequent genetic abnormality: the molecular genetic constitution of supratentorial PNETS has not been systematically studied. We therefore examined 8 hemispheric PNETs and 35 medulloblastomas with 17p restriction fragment length polymorphism (RFLP) and microsatellite markers. We also examined the TP53 tumor suppressor gene by a combined polymerase chain reaction-denaturing gradient gel (PCR-DGGE) technique. Our results showed that all of the 17p markers tested were preserved in all of the supratentorial PNET specimens. In contrast, loss of distal chromosome arm 17p was detected in 37% of the medulloblastomas. Analysis of the TP53 gene showed 2 mutations in the medulloblastomas and no mutations in the supratentorial tumors. These results show that the most common molecular genetic abnormality in infratentorial PNETS is absent in their supratentorial counterparts and suggests that alternative pathways and genetic events may be involved in their etiology.

Molecular genetic analysis of chromosome arm 17p and chromosome arm 22q DNA sequences in sporadic pediatric ependymomas

Ependymomas are glial tumors of the brain and spinal cord occurring both sporadically and in a familial syndrome, neurofibromatosis type 2 (NF2). Previous analyses performed on specimens obtained predominantly from adult patients have shown loss of DNA sequences from chromosome arm 22q, which is the location of the NF2 gene. Previously, we documented the consistent loss of chromosome arm 17p DNA in medulloblastoma and astrocytoma, which are the most common brain tumors in children. Although mutation of the TP53 gene located on 17p is the most frequent genetic mutation in all adult tumor types, such mutations are rare in most childhood brain tumors investigated to date. We studied a series of pediatric ependymoma specimens (16 intracranial and 2 spinal) for loss of 17p and 22q DNA sequences and for mutation of the TP53 and NF2 genes. None of the children had the clinical stigmata of NF2. We detected loss of 17p DNA sequences in 9 of the 18 specimens (50%); in 7 of 9 of these specimens (78%), the 144-D6 marker was deleted. In contrast, only 2 of these same 18 specimens (11%) showed loss of 22q DNA. One TP53 gene mutation was detected in a child from a cancer kindred. No mutations were detected in the NF2 gene. Our results suggest that loss of chromosome arm 17p DNA sequences is common in sporadic pediatric ependymomas and that, in contrast to ependymomas in adults, deletion of chromosome arm 22q sequences is rare. Furthermore, TP53 and NF2 gene mutations do not play an important role in the etiology of sporadic pediatric ependymomas.

Response of six major histocompatibility (B) complex recombinant haplotypes to Rous sarcomas

Six B complex recombinants, BR1 (F24-G23), BR2 (F2-G23), BR3 (F2-G23), BR4 (F2-G23), BR5 (F21-G19), and BR6 (F21-G23), from the fourth backcross generation to highly inbred line UCD 003 (B17B17) were studied for their response to Rous sarcomas. Eight hatches were produced from heterozygous (BRnB17) parents. Chicks were wingweb inoculated with 50 pock-forming units of Rous sarcoma virus (RSV) at 6 wk of age. A tumor profile index (TPI), based on degree of tumor regression, was evaluated by analysis of variance. BR2, BR3, and BR4 are serologically similar F2-G23 recombinants. Haplotype B2, the origin of BF2, is a known tumor regressor, yet BR2BR2 chickens had a significantly lower TPI than BR3BR3 and BR4BR4 chickens. The TPI of BR2BR2 (F2-G23) chickens was also significantly lower than the TPI of chickens homozygous for BR1 (F24-G23) and BR5 (F21-G19). The BR6BR6 (F21-G23) chickens had significantly lower TPI than all homozygotes except BR2BR2 (F2-G23). Among heterozygous genotypes, BR2B17, BR5B17, and BR6B17 differed significantly from BR1B17, BR3B17, and BR4B17. These results suggest that serologically similar recombinants that contain (F2-G23) possess different genes affecting tumor regression. In addition, degrees of tumor regression in BR5 (F21-G19) and BR6 (F21-G23), both of which contain BF21, may be due to genetic differences within the B-F/B-L or B-G regions.

Porphyrogenic properties of the terpenes camphor, pinene, and thujone (with a note on historic implications for absinthe and the illness of Vincent van Gogh)

Camphor, alpha-pinene (the major component of turpentine), and thujone (a constituent in the liqueur called absinthe) produced an increase in porphyrin production in primary cultures of chick embryo liver cells. In the presence of desferrioxamine (an iron chelator which inhibits heme synthesis and thereby mimics the effect of the block associated with acute porphyria), the terpenes enhanced porphyrin accumulation 5- to 20-fold. They also induced synthesis of the rate-controlling enzyme for the pathway, 5-aminolevulinic acid synthase, which was monitored both spectrophotometrically and immunochemically. These effects are shared by well-known porphyrogenic chemicals such as phenobarbital and glutethimide. Camphor and glutethimide alone led to the accumulation of mostly uro- and heptacarboxylporphyrins, whereas alpha-pinene and thujone resulted in lesser accumulations of porphyrins which were predominantly copro- and protoporphyrins. In the presence of desferrioxamine, plus any of the three terpenes, the major product that accumulated was protoporphyrin. The present results indicate that the terpenes tested are porphyrogenic and hazardous to patients with underlying defects in hepatic heme synthesis. There are also implications for the illness of Vincent van Gogh and the once popular, but now banned liqueur, called absinthe.

Temporal response of neurons to ambient heating in the preoptic and septal area of the unanesthetized rabbit

The firing rates of single neurons were recorded in the septal and preoptic areas of unanesthetized rabbits during brief periods of ambient heating. The temporal response for neurons responsive to ambient temperature were calculated as the interval of time between the onset of heating and the point at which the unit's activity reached 63% (i.e. 1-1/e) of its total change in activity. Thirty-one neurons were isolated in 5 rabbits. Fourteen neurons were facilitated, 10 were inhibited and 7 were unaffected by heating. Temporal responses ranged from less than 5 to 122 s. We observed a bimodal relationship in the number of neuronal responses to ambient temperature vs temporal response: a sharp 0- to less than 10-s peak comprising 22% of all responses and a relatively broad peak with a mode of 60 to less than 70 s. These data resemble the temporal response patterns of thermally excitable neurons throughout the central nervous system.

Percutaneous stone extraction from 200 patients

More than 200 patients have undergone percutaneous stone extraction at our institution. With the percutaneous nephrostomy tract as the conduit to the urinary tract we have removed 95 per cent of the pelviocaliceal stones and 80 per cent of the ureteral stones with grasping forceps, baskets, ultrasonic lithotripsy or a combination of these procedures. Complications were few and patients returned to work sooner than after an open operation.

"Early" carcinoma of the breast: evaluation of regional therapy and features influencing prognosis

Between 1944 and 1969, 192 women with carcinoma of the breast were treated at The University of Texas System Cancer Center M. D. Anderson Hospital and Tumor Institute by standard radical mastectomy for small outer quadrant lesions and pathologically negative axillary lymph nodes. Twenty percent of these patients with "localized disease" eventually had disseminated breast cancer. Various patient, hormonal, genetic, and pathologic factors were found to have little influence on the prognosis. Patterns of metastatic disease revealed that these patients did not have a unique form of breast cancer, but apparently an earlier stage in the spectrum of advancing disease. The results of this study appear to represent the best that can be obtained with regional therapy for carcinoma of the breast and emphasize the need for reliable adjuvant therapy.

Validation of a dietary record system for the estimation of daily cholesterol intake in individual outpatients

In order to develop a reliable system for measuring daily cholesterol intake in individual outpatients, studies were undertaken to establish the shortest time period (in days) for which it is necessary to obtain daily food intake records. Three volunteers were trained in dietary record-keeping and portion-size assessment, and instructed to self-select a low-cholesterol diet for 20 days. During the study period they maintained daily dietary records and collected dummy diets. Comparisons of cholesterol intake calculated from the dietary records (mean 144 mg/day, SD +/- 13, n = 60) to the values from chemical analysis (118 +/- 28 mg/day) demonstrated that the calculated values were higher (mean 19%). More importantly, it was found that a minimum of 9 days' records of dummy diet analyses were required in order to reach an estimate of daily cholesterol intake that varied by less than 10% from the mean of the 20-days' values. In 100 outpatients trained to adhere to a moderately low-cholesterol intake and who maintained sequential dietary records for 9 days, it was found that the mean daily intake was 251 mg/day but that individual patients exhibited substantial daily variations in cholesterol intake (average coefficient of variation = 54%, range = 8.5 to 121.2%). These results demonstrate that, under conditions of training in dietary record-keeping and portion-size assessment, adherence to a low-cholesterol diet, and with collection of at least 9 days of dietary records, a reliable quantitative estimate of daily dietary cholesterol intake can be obtained in free-living outpatient populations.

Prognosis and treatment in minimal breast cancer

Of 176 patients with minimal breast cancer, 138 had intraductal carcinoma in situ, 21 minimally invasive carcinoma, and 17 lobular carcinoma in situ. Various modalities of treatment were used including radical, modified radical, and simple mastectomy with and without radiation therapy. Long-term postoperative follow-up was available in all but five patients and ranged from one year to twenty-one years. Actuarial analysis projected a twenty year survival of 93.2 per cent for the entire group. Analysis of survival figures based on each of the several treatment modalities showed no definite advantage of one form of treatment over another. The data suggest that minimal breast cancer is a prognostically favorable diagnosis, provided invasive carcinoma is not present or does not develop in the opposite breast. It is also indicated that breast cancer is potentially a bilateral disease and that follow-up and treatment of the opposite breast must be of major concern in the care of these patients.

Carcinoma of the breast: analysis of total lymph node involvement versus level of metastasis

The histologic presence of axillary lymph node metastasis is the most commonly used indicator or prognosis for patients with operable breast cancer. The record of 385 patients treated by 380 radical mastectomies between the years 1944 and 1972 were reviewed to clarify this. The axillary nodes recovered were evenly distributed. The median number of positive lymph nodes at each level was two; 50% had involvement of only one level. The number of lymph nodes identified increased with the number of positive nodes. When compared with similar patients, survival curves for those having a single involved node and also those having multiple metastatic nodes were similar whether the node were in the proximal, middle, or distal levels. The 10-year determinate survival for patients with fewer than five positive positive nodes was just under 50%. High positive nodal counts, or involvement of more than one level, were associated with local recurrence of disease.