Local Growth Control Research Articles

Causes of Death in Patients With Brain Metastases.

Advances in targeted therapies and wider application of stereotactic radiosurgery (SRS) have redefined outcomes of patients with brain metastases. Under modern treatment paradigms, there remains limited characterization of which aspects of disease drive demise and in what frequencies. This study aims to characterize the primary causes of terminal decline and evaluate differences in underlying intracranial tumor dynamics in patients with metastatic brain cancer. These fundamental details may help guide management, patient counseling, and research priorities. Using NYUMets-Brain-the largest, longitudinal, real-world, open data set of patients with brain metastases-patients treated at New York University Langone Health between 2012 and 2021 with SRS were evaluated. A review of electronic health records allowed for the determination of a primary cause of death in patients who died during the study period. Causes were classified in mutually exclusive, but collectively exhaustive, categories. Multilevel models evaluated for differences in dynamics of intracranial tumors, including changes in volume and number. Of 439 patients with end-of-life data, 73.1% died secondary to systemic disease, 10.3% died secondary to central nervous system (CNS) disease, and 16.6% died because of other causes. CNS deaths were driven by acute increases in intracranial pressure (11%), development of focal neurological deficits (18%), treatment-resistant seizures (11%), and global decline driven by increased intracranial tumor burden (60%). Rate of influx of new intracranial tumors was almost twice as high in patients who died compared with those who survived ( P < .001), but there was no difference in rates of volume change per intracranial tumor ( P = .95). Most patients with brain metastases die secondary to systemic disease progression. For patients who die because of neurological disease, tumor dynamics and cause of death mechanisms indicate that the primary driver of decline for many may be unchecked systemic disease with unrelenting spread of new tumors to the CNS rather than failure of local growth control.

Combined treatment of rectal cancer with moderate risk of tumor progression

To increase the effectiveness of combined treatment in patients with rectal cancer and moderate risk of progression based on the concept of polyradiomodification (PRM). The study included 337 patients with rectal cancer and moderate risk of tumor progression. A short course of radiotherapy (cRT) (5x5 Gy) combined with several radiomodifiers (cRT+PRM) was performed in 147 (43.6%) patients. Other 190 (56.4%) patients underwent cRT. The following radio modifiers were used: three-time application of local microwave hyperthermia (Yacht-3 or Yacht-4 devices), two-time intrarectal delivery of a biopolymer composition with Metronidazole before the 3rd and 5th irradiation sessions and two-week oral administration of Capecitabine (Xeloda) at a daily dose of 2.0 g/m2. Surgery was performed in 4-6 weeks after radiotherapy. CRT+PRM program increased 5-year relapse-free survival up to 81.3% compared to 60.3% after cRT alone (p=0.0003) due to significant reduction of the incidence of cancer recurrence from 8.4% to 0.7% (p=0.0013). More effective local growth control expanded the indications for sphincter-sparing surgery. These procedures were performed in 89.1% and 70.5% of patients, respectively (p=0.00001). In the cRT+PRM group, sphincter-sparing surgery reduced incidence of cancer recurrence from 13.7% to 0.8% (p=0.0110), distant metastases - from 23.9% to 13.7% (p=0.00349). Radiomodification in neoadjuvant radiotherapy is justified in patients with moderate risk of tumor progression, improves long-term results and increases the incidence of sphincter-sparing surgery.

Combining abiraterone and radiotherapy in metastatic castration-resistant prostate cancer: a review of current evidence.

Prostate cancer is the second most frequent cancer worldwide, with a very high rate of progression despite treatment. The most aggressive form of the disease is known as castration-resistant prostate cancer, which carries a poor prognosis. We reviewed available literature regarding the combination of abiraterone acetate antihormonal drug and ablative radiation therapy for the treatment of metastatic castration-resistant prostate cancer. This dual treatment may enhance the effects of second-line hormonal therapy, as radiotherapy renders cancer cells more prone to immune-mediated cytotoxicity. Moreover, radiotherapy exerts its effect both on directly irradiated cells and on other distant tissues, with an abscopal effect, already demonstrated in other solid tumors. This combination treatment is safe and effective, with few adverse events. Moreover, it is of paramount importance in patients with oligoprogression of the primary disease, when current guidelines recommend continuing abiraterone treatment. Ablative radiation therapy is a noninvasive, nontoxic treatment with very high efficacy on local tumor growth control. In the available literature, the combination of radiation therapy and abiraterone acetate has prolonged both overall survival and progression-free survival, with a positive impact also on locoregional recurrence and distant metastases.

Cellular and Molecular Background Underlying the Diversity in Therapeutic Responses Between Primary Tumours and Metastases

Metastasis, also called secondary neoplastic disease, is a tumour newly formed in a site different from that of origin, as a consequence of cancer progression and dissemination largely through blood and lymphatic vessels. The ability to form metastases is the main property that distinguishes malignant from benign tumours. Treatments for metastatic cancer are similar in practice to those for primary tumours, but such treatments are mostly palliative; indeed, almost all deaths caused by solid tumours occur in the metastatic phase. Increasing evidence supports the concept that therapies for primary tumours are inadequate to treat metastasis and can even promote formation of metastases, while exerting local growth control. Furthermore, recurrent tumours, which are denoted by increased aggressiveness and therapy resistance in comparison with the primary tumour, have an increased metastatic potential. Genetic modifications occurring during tumour progression lead to substantial differences between the primary and metastatic tumours. This emphasises the importance of designing novel therapies for metastasis. In the last decade, a number of studies have contributed to the understanding of the genetic rearrangements underlying the conversion of cancer cells into the metastasis founder cells. The present article aims at reviewing recent advances in metastasis research and attempts to discuss the reasons for which the therapeutic strategies against primary tumours may not satisfactorily address their metastatic counterparts.

Staged image guided robotic radiosurgery for optic nerve sheath meningiomas

Objective: Optic nerve sheath meningiomas (ONSMs) represent the most challenging lesions involving the optic pathways: Microsurgery is not indicated and classical single-stage radiosurgery appears to be too risky due to the expected destruction of the common blood supply with consequent loss of vision. Staged radiosurgery might be one treatment option because it exploits the ability of normal tissues to repair sub-lethal radiation-induced damage, offering a chance to control tumor growth while sparing function. Staged robotic radiosurgery was offered to 5 patients harboring ONSMs with the aim of sparing vision while achieving local growth control.Patients and Methods: Five patients with ONSM presenting with visual field deficits and loss of visual acuity were treated with staged CyberKnife radiosurgery, receiving 20 Gy in 4 stages (5 Gy per stage). Treatment planning was based on contrast-enhanced thin-slice CT (1.25 mm thickness for the first three cases, 0.5 mm for the last two) and volumetric MR imaging (1.5 T for the first three cases, 3 T for the last two). An interval of 24 hours was strictly observed between stages. Visual acuity and visual fields were assessed in all patients immediately prior to treatment and at intervals of 6 months thereafter. Follow-up MRIs were performed every 6 months for 2 years, then once per year.Results: The entire procedure, inclusive of imaging, treatment planning and treatment delivery, was performed in 5 days. Irradiation required approximately 45 min per stage. Mean tumor volume was 2.94 cc (range: 0.8–6.4 cc). Treatment was well tolerated in all patients. Follow-up ranged from 36 to 74 months. Local growth control was achieved in all patients. Restoration of normal vision was experienced by 4 patients 6 to 12 months after the treatment. One patient, who was also affected by diabetic retinopathy, showed a modest improvement after 6 months, remaining stable thereafter.Conclusion: Staged CyberKnife radiosurgery provides a fast and well-tolerated non-invasive treatment with excellent visual outcomes. If these preliminary results are confirmed by larger series, staged radiosurgery could be proposed as a first-line treatment for ONSM.

Modeling local growth control decisions in a multi-city case: Do spatial interactions and lobbying efforts matter?

Our article analyzes the determinants of local growth control decisions, which are modeled as the result of a political struggle between different groups of voters and organized lobbies. We show that under specific hypotheses, a higher homeownership rate can induce lower levels of controls. Considering residential choices as endogenous to growth control policies, the local decisions to control growth become strategically interdependent. Assuming imperfect mobility, we show that a spatial econometric specification can be directly derived from our theoretical model. Our empirical analysis concerning the determinants of the “taxe locale d’équipement”, a French local development tax, is thus naturally based on spatial econometrics. Its results confirm the major predictions of our model.

Gamma Knife surgery for metastatic brain tumors from primary breast cancer: treatment indication based on number of tumors and breast cancer phenotype

The goal of this study was to analyze prognostic factors for local tumor control and survival and indications for initial treatment with the Gamma Knife in patients with up to 10 metastatic brain tumors from primary breast cancer. Outcomes were retrospectively reviewed in 101 women with a total of 600 tumors, who underwent Gamma Knife surgery (GKS) for metastatic brain tumors between April 1992 and December 2008 at 1 institution. The inclusion criteria were up to 10 brain metastases, maximum diameter of tumor < 3 cm, and total tumor volume < 15 cm(3). The exclusion criteria were poor systemic condition, presence of carcinomatous meningitis, and previous whole brain radiation treatment and/or craniotomy. The mean tumor volume at GKS was 3.7 cm(3) (range 0.016-14.3 cm(3)). The mean margin dose was 19 Gy (range 8-30 Gy). Neuroimaging showed that the local tumor growth control rate was 97%, and the tumor response rate was 82.3%. Larger tumor volume (p = 0.001) and lower margin dose (p = 0.001) were significant adverse prognostic factors for local tumor growth control according to a multivariate analysis. The number of brain metastatic lesions was 4 or fewer in 76 patients and 5 or more in 25 patients. The median overall survival time was 13 months. Multivariate analysis revealed that the presence of extracranial metastases (p = 0.041) and lesions that were not the human epidermal growth factor receptor-2 (HER2)-positive type (p = 0.001) were significant adverse prognostic factors for overall survival. The number of brain metastases was not statistically significant, except for a single metastasis. The median new lesion-free survival time after initial GKS was 9 months. Five or more lesions at initial GKS (p = 0.007) and younger patient age (p = 0.008) reduced survival significantly. The prevention of neurological death after GKS was 93.9% at 1 year, and a lower Karnofsky Performance Scale score (p = 0.009) was the only unfavorable factor. Median overall survival associated with the HER2-positive phenotype was significantly longer than survival associated with the other phenotypes (luminal and triple-negative). There were no statistically significant differences between the 3 breast cancer phenotypes for the incidence of new brain metastases after initial GKS. Initial GKS resulted in excellent local tumor control rates, which were associated with prolonged survival and a low risk of neurological death for patients with up to 10 metastatic brain tumors from primary breast cancer. The authors recommend periodic clinical and neuroradiological follow-up examinations after GKS in patients with 5 or more lesions at initial GKS, because they carry a high risk of development of new brain metastases, and in patients with the HER2-positive phenotype, because they tend to have a favorable prognosis in overall survival. Last, the authors recommend additional GKS or whole-brain radiation treatment for salvage treatment if new brain metastases occur.

Gamma Knife surgery for brain metastases from colorectal cancer

The outcomes after Gamma Knife surgery (GKS) were retrospectively analyzed in patients with brain metastases from radioresistant primary colorectal cancer to evaluate the efficacy of GKS and the prognostic factors for local tumor control and overall survival. The authors reviewed the medical records of 152 patients with 616 tumors. The group included 102 men and 50 women aged 35-85 years (mean age 64.4 years), who underwent GKS for metastatic brain tumors from colorectal cancer between April 1992 and September 2008 at Yokohama Rosai Hospital. The mean prescription dose to the tumor margin was 18.5 Gy (range 8-30 Gy). The mean tumor volume at GKS was 2.0 cm(3) (range 0.004-10.0 cm(3)). The primary tumors were located in the colon in 88 patients and the rectum in 64. The median interval between the diagnosis of primary lesions and the diagnosis of brain metastases was 27 months (range 0-180 months). The median neuroradiological follow-up period after GKS was 3 months (mean 6.4 months, range 1-93 months). The local tumor growth control rate, based on MR imaging, was 91.2%. The significant factors for unfavorable local tumor growth control, based on multivariate analysis, were larger tumor volume (p = 0.001) and lower margin dose (p = 0.016). The median overall survival time was 6 months. Lower Karnofsky Performance Scale (KPS) score (p = 0.026) and the presence of extracranial metastases (p = 0.004) at first GKS were significantly correlated with poor overall survival period in multivariate analysis. The cause of death was systemic disease in 112 patients and neurological disease in 13 patients. Leptomeningeal carcinomatosis was significantly correlated with a shorter duration of neurological survival in multivariate analysis (p < 0.0001). Gamma Knife surgery is effective for suppression of local tumor growth in patients with brain metastases from radioresistant colorectal primary cancer. Therefore, clinical and radiological screening of intracranial metastases for patients with lower KPS scores and/or the presence of extracranial metastases as well as follow-up examinations after GKS for brain metastases should be performed periodically in patients with colorectal cancer, because the neurological prognosis is improved by initial and repeat GKS for newly diagnosed or recurrent tumors leading to a prolonged high-quality survival period.

Gamma knife stereotactic radiosurgery yields good long-term outcomes for low-volume uveal melanomas without intraocular complications

We present the outcomes of 35 uveal melanoma patients treated with gamma knife stereotactic radiosurgery. All cases were previously untreated. During follow-up, regular MRI examinations were used to detect any changes in tumor size and estimate the local long-term tumor control rate. Treatment-related complications were also recorded. During follow-up, systemic dissemination was observed in two patients, one of whom died of metastases. The most frequent complication was retinal detachment (17.1%). Three patients required enucleation. Cumulative 1-year and 3-year local tumor growth control rates were 97% and 83%, respectively. The mean and median times to local tumor progression were 48.0 and 51.7 months, respectively. Gamma knife surgery may be a suitable alternative for the treatment of low-volume uveal tumors without intraocular complications, as the control rate and long-term outcomes compare favorably with those of surgical excision and brachytherapy.

Robotic image-guided radiosurgery for the treatment of neoplastic vertebral pain

Metastatic spinal lesions are a common event in cancer patients. Spinal metastases usually involve the vertebral bodies and are characterized by severe pain. Surgical treatment, as a consequence of its high invasivity, is rarely offered to patients with metastatic disease and expected limited life span. Spinal radiosurgery provides high rates of pain and local growth control in association with limited risk of neurological complications. The use of radiosurgery to treat spinal lesions has been strongly facilitated by the development of image-guided robotic radiosurgery, a technique able to deliver stereotactic irradiation to intra- and extracranial targets. Despite the exponential increase of treatments delivered to the spine using this novel approach and the growing number of papers reporting the outcomes of spine radiosurgery in terms of local growth control and analgesia following treatment of patients with metastatic and benign lesions of the spine, the awareness of the general medical public to the use of this technique remains limited. This paper aims to review the role of radiosurgery in the treatment of vertebral metastases and benign tumors and its efficacy in terms of pain and local growth control.

Why Do Communities Mobilize against Growth: Growth Pressures, Community Status, Metropolitan Hierarchy, or Strategic Interaction?

ABSTRACT:Findings from this study challenge the conventional wisdom about the motivations for local growth control. Using data of California ballot box growth controls merged with city level demographic and housing data from the U.S. Census Bureau, logit models are estimated to test four hypotheses for why communities mobilize against growth. Of the four hypotheses, growth pressures, community status, metropolitan hierarchy, and strategic interaction, the only hypothesis that was strongly supported by the logistic regression analyses was strategic interaction. Support for the strategic interaction hypothesis reveals that jurisdictions located in regions where growth control policies are more abundant have a higher probability of mobilizing against growth. In other words, jurisdictions’ growth control policies influence the growth decisions made by neighboring jurisdictions within the same region. One of the most surprising findings in the logistic regression analyses is that low-income suburbs are significantly more likely to mobilize against growth than high-income suburbs. These results refute the commonly held belief that growth control is strictly a concern of elite communities and suggest that residents of low-income suburbs may be turning to the ballot box to control growth because their communities are the locations of choice for noxious land uses.

Local Growth Control at the Ballot Box: Real Effects or Symbolic Politics?

ABSTRACT:Growth control regulations are pervasive in local jurisdictions throughout the United States; yet there is still much uncertainty about their effectiveness in slowing down or halting growth. Moreover, there is considerable debate over whether there are unintended (or sometimes intended) exclusionary consequences that disproportionately affect minority and low-income populations. Employing multiple regression analyses, this study examines the effects of growth control ballot measures, adopted by voters, on housing growth and sociodemographic change in local jurisdictions. The findings from the multiple regression analyses reveal that cities in which growth controls were adopted at the ballot box do have slower rates of housing growth. There is also evidence that ballot box growth controls reduce growth in Hispanic and lower-income populations. Overall, the results from this study suggest that the adoption of ballot box growth controls is not merely “symbolic politics,” but has real measurable consequences on housing growth. Unfortunately, growth controls adopted by the ballot box may also contribute to the sociospatial segregation of cities by race/ethnicity and income.

Growth Management Revisited: Efficacy, Price Effects, and Displacement

This article uses California as its lens to focus on three unresolved questions concerning the effectiveness of local growth control and management (LGC&M) programs. I conclude that some types of LGC&M programs, principally residential caps, annexation controls, and voter-enacted super-majority approval requirements, do appear to significantly limit population growth in the cities that adopt them. I also find that LGC&M programs that do not constrain housing production below their communities' shares of regional demand for housing are not principally responsible for high housing prices and rents. Finally, LGC&M programs are associated with an increased likelihood of infill development in the cities that adopt them, and with growth displacement to nearby communities.

Understanding Spatial and Temporal Processes of Urban Growth: Cellular Automata Modelling

An understanding of the dynamic process of urban growth is a prerequisite to the prediction of land-cover change and the support of urban development planning and sustainable growth management. The spatial and temporal complexity inherent in urban growth requires the development of a new simulation approach, which should be process-oriented and have a strong interpretive element. In this paper the authors present an innovative methodology for understanding spatial processes and their temporal dynamics on two interrelated scales—the municipality and project scale—by means of a multistage framework and a dynamic weighting concept. The multistage framework is aimed at modelling local spatial processes and global temporal dynamics by the incorporation of explicit decisionmaking processes. It is divided into four stages: project planning, site selection, local growth, and temporal control. These four stages represent the interactions between top-down and bottom-up decisionmaking involved in land development in large-scale projects. Project-based cellular automata modelling is developed for interpreting the spatial and temporal logic between various projects that form the whole of urban growth. Use of dynamic weighting is an attempt to model local temporal dynamics at the project level as an extension of the local growth stage. As nonlinear function of temporal land development, dynamic weighting can link spatial processes and temporal patterns. The methodology is tested with reference to the urban growth of a fast growing city—Wuhan, in the People's Republic of China—from 1993 to 2000. The findings from this research suggest that this methodology can be used to interpret and visualise the dynamic process of urban growth temporally and transparently, globally and locally.

Molecular Regulation of the IGF-Binding Protein-4 Protease System in Human Fibroblasts: Identification of a Novel Inducible Inhibitor

The IGF-binding protein-4 (IGFBP-4) protease system is an important regulator of local IGF bioavailability and cell growth. Recently, the IGF-dependent IGFBP-4 protease secreted by cultured human fibroblasts was identified as pregnancy-associated plasma protein A (PAPP-A). In pregnancy serum, PAPP-A circulates as a disulfide-bound complex with the precursor form of major basic protein (pro-MBP), and in this complex PAPP-A’s proteolytic activity is not evident. In this study we analyzed the IGFBP-4 protease system in normal human fibroblasts to determine regulation outside of pregnancy. Treatment with the phorbol ester tumor promoter, β-phorbol 12,13-didecanoate (β-PDD), resulted in time-dependent inhibition of the IGF-dependent IGFBP-4 protease activity in cell-conditioned medium, which was evident at 6 h and complete by 24 h. PAPP-A mRNA was constitutively expressed in control cells, and levels were decreased only after 24 h of β-PDD treatment. Secretion of PAPP-A protein into conditioned medium did not change with β-PDD treatment. On the other hand, pro-MBP mRNA was undetectable in control human fibroblasts, and treatment with β-PDD induced pro-MBP mRNA and protein expression within 6 h. β-PDD-induced pro-MBP mRNA expression and protease inhibition were blocked with an inhibitor of RNA synthesis, actinomycin D. Actinomycin D had no effect on PAPP-A mRNA levels in the absence or presence of β-PDD. Similarly, transformation of human fibroblasts with simian virus 40 large T antigen resulted in the synthesis of pro-MBP mRNA and protein and inhibition of IGFBP-4 protease activity. Coculture of fibroblasts with cells transfected with pro-MBP cDNA resulted in inhibition of IGFBP-4 proteolytic activity without having any effect on PAPP-A synthesis. In summary, phorbol ester tumor promoters and simian virus 40 transformation regulate IGFBP-4 proteolysis in human fibroblasts through induction of a novel inhibitor of PAPP-A, pro-MBP. These findings expand our understanding of the IGFBP-4 protease system and suggest an additional level of local cell growth control.

Molecular Regulation of the IGF-Binding Protein-4 Protease System in Human Fibroblasts: Identification of a Novel Inducible Inhibitor

The IGF-binding protein-4 (IGFBP-4) protease system is an important regulator of local IGF bioavailability and cell growth. Recently, the IGF-dependent IGFBP-4 protease secreted by cultured human fibroblasts was identified as pregnancy-associated plasma protein A (PAPP-A). In pregnancy serum, PAPP-A circulates as a disulfide-bound complex with the precursor form of major basic protein (pro-MBP), and in this complex PAPP-A's proteolytic activity is not evident. In this study we analyzed the IGFBP-4 protease system in normal human fibroblasts to determine regulation outside of pregnancy. Treatment with the phorbol ester tumor promoter, beta-phorbol 12,13-didecanoate (beta-PDD), resulted in time-dependent inhibition of the IGF-dependent IGFBP-4 protease activity in cell-conditioned medium, which was evident at 6 h and complete by 24 h. PAPP-A mRNA was constitutively expressed in control cells, and levels were decreased only after 24 h of beta-PDD treatment. Secretion of PAPP-A protein into conditioned medium did not change with beta-PDD treatment. On the other hand, pro-MBP mRNA was undetectable in control human fibroblasts, and treatment with beta-PDD induced pro-MBP mRNA and protein expression within 6 h. beta-PDD-induced pro-MBP mRNA expression and protease inhibition were blocked with an inhibitor of RNA synthesis, actinomycin D. Actinomycin D had no effect on PAPP-A mRNA levels in the absence or presence of beta-PDD. Similarly, transformation of human fibroblasts with simian virus 40 large T antigen resulted in the synthesis of pro-MBP mRNA and protein and inhibition of IGFBP-4 protease activity. Coculture of fibroblasts with cells transfected with pro-MBP cDNA resulted in inhibition of IGFBP-4 proteolytic activity without having any effect on PAPP-A synthesis. In summary, phorbol ester tumor promoters and simian virus 40 transformation regulate IGFBP-4 proteolysis in human fibroblasts through induction of a novel inhibitor of PAPP-A, pro-MBP. These findings expand our understanding of the IGFBP-4 protease system and suggest an additional level of local cell growth control.

A novel bystander effect involving tumor cell-derived Fas and FasL interactions following Ad.HSV-tk and Ad.mIL-12 gene therapies in experimental prostate cancer

To enhance the NK population induced by Herpes Simplex virus thymidine kinase (HSV-tk) gene transduction and ganciclovir (GCV) treatment, adenovirus-mediated (Ad) expression of IL-12 was added to Ad.HSV-tk + GCV as combination gene therapy. This approach resulted in improved local and systemic growth suppression in a metastatic model of mouse prostate cancer (RM-1). In vitro assay of tumor infiltrating lymphocytes noted superior lysis of both RM-1 and Yac-1 targets with combination therapy, but in vivo depletion of NK cells only negatively impacted on systemic growth inhibition. TUNEL assay of primary tumors noted induction of apoptosis between two and four times higher than controls lasting for 6-8 days post-vector injection. After demonstrating that Ad.HSV-tk/GCV and Ad.mIL-12-induced IFN-gamma independently up-regulated expression of FasL and Fas, respectively, studies examined tumor cell-mediated death through Fas/FasL-induced apoptosis as a mechanism of primary tumor growth suppression. In vitro, combination therapy at low vector doses resulted in synergistic growth suppression, which could be negated by the addition of anti-FasL antibody. In vivo co-inoculation of an adenovirus expressing soluble Fas resulted in combination therapy-treated tumors, which were three times larger than expected, and a reduction in apoptosis to baseline levels. In FasL knockout mice, combination therapy maintained the superior results experienced in wild-type mice, indicating that tumor cell, not host cell FasL, was responsible for Fas transactivation. Therefore, the combination of Ad.HSV-tk/GCV + Ad.mIL-12 results in enhanced local growth control via apoptosis due to tumor cell expression of Fas and FasL and improved anti-metastatic activity secondary to a strong NK response.

The Effects of Local Growth Controls on Regional Housing Production and Population Redistribution in California

Based on two surveys of 490 Californian cities and counties, the study examines the effects of local growth-control enactment between 1979 and 1988 on net housing construction between 1980 and 1990. It is shown that local growth-management measures significantly displaced new construction, particularly rental housing, possibly exacerbating the expansion of the metropolitan areas into the interiors of the state. Further, the measures impacted low-income households and minorities particularly. Not all growth-control measures were associated with this change. Measures which limited available land or which downsized existing zoning had stronger effects.

Recurrence in meningeal hemangiopericytomas

BACKGROUND Meningeal hemangiopericytomas are more aggressive than typical meningiomas, with a high rate of recurrence and distant metastases. The question of whether a correlation exists between prognosis and histologic features remains controversial. CASE DESCRIPTION We report two cases of recurrent meningeal hemangiopericytomas. Although local growth control of the tumor was obtained by tumor removal and irradiation in a 38-year-old male patient (Case 1) with a recurrent tentorial tumor, the tumor disseminated and metastasized extracranially within a short period after treatment, leading to rapid deterioration. Another 38-year-old female patient (Case 2) with a recurrent orbital tumor had a favorable outcome after tumor removal. The Ki-67 proliferative index using the MIB-1 monoclonal antibody increased as the tumor recurred in Case 1 (2.5%, 7.9%, and 15.7%), but did not change between primary and recurrent tumors of Case 2 (4.2%, 3.1%). Immunostaining for p53 protein in Case 1 was negative at the first resection, and became positive at the second and third resections, whereas in Case 2, it was negative in both the primary and recurrent tumors. CONCLUSIONS Our results suggest that p53 protein accumulation with a high proliferative potential is a useful marker to estimate malignant progression in meningeal hemangiopericytomas.

Spatial Impacts of Locally Enacted Growth Controls: The San Francisco Bay Region in the 1980s

In this paper the regionwide, spatial consequences of locally enacted growth controls are examined on the basis of a case study of the San Francisco Bay Region. A quasi-experimental methodology is employed. An ex post projection of population distribution among the region's cities in 1990 is generated by means of a model that represents the before growth control urban structure. A comparison is then made between the projected distribution and the actual distribution depicted by the 1990 census data. The differences, indexed as percentage projection errors, provide an empirical basis for assessing the impacts of local growth-control policies. Statistical analyses of the projection errors indicate that the local policies have caused a major redistribution of population growth from growth-controlled cities to the rest of the region. Geographic information systems-based spatial analyses of the projection errors suggest that the spatial process of growth control is driven primarily by NIMBYism. The main conclusions are that: (1) the existing decentralized system of growth management has created a spatial pattern of urban development that has undesirable economic and distributional effects; and (2) a carefully developed coordinated regional system of growth management is preferable because many critical growth problems can be addressed appropriately only at the regional or metropolitan level.