Biomedical subjects

A Felix

Publications and source records attributed to A Felix.

At least 19 recordsLinked to original sources

PubMed2002

Intracapsular carcinoma ex pleomorphic adenoma. Report of a case with unusual metastatic behaviour.

Intracapsular carcinomas ex pleomorphic adenoma are exceedingly rare salivary glands tumours, known to have a benign clinical behaviour with metastatic unrecognised potential. We report a case of a 57-year-old female patient presenting with a typical example of intracapsular carcinoma ex pleomorphic adenoma of the parotid gland and evidence of ipsilateral cervical lymph node metastases two years before. The behaviour of this unique case illustrates the disputed malignancy of carcinomas arising within encapsulated pleomorphic adenomas.

Adenoma, Pleomorphic↗

PubMed2000

Lamb production and forage quality under a forage system consisting of AU Triumph tall fescue and Tifton 44 bermudagrass.

The lamb production potential and forage quality of a forage system consisting of AU Triumph fescue and Tifton 44 bermudagrass was studied over a period of two consecutive years. Each spring, 60 yearling Suffolk ewes and 40 wethers were divided into two groups and allowed to graze two replicated 1ha AU Triumph paddocks continuously. At the end of the spring grazing season, both groups were transferred to two replicated 1ha Tifton 44 paddocks for summer grazing. Body weight was recorded fortnightly and composite forage samples analyzed for chemical composition, in vitro dry matter disappearance (IVDMD) and in vitro organic matter disappearance (IVOMD) at the end of the study. Mean crude protein (CP), ether extract (EE), ash, neutral-detergent fiber (NDF), acid-detergent fiber (ADF), cellulose, lignin, IVDMD and IVOMD contents of AU Triumph fescue were 13.26, 1.86, 7.38, 69.4, 36.37, 29.2, 6.81, 64.44 and 62.88%, respectively. The corresponding values for Tifton 44 bermudagrass were 7.5, 1.01, 5.2, 78.3, 41.0, 28.3, 8.8, 56.97 and 55.61%. Average daily gain (ADG) and lamb gain per hectare on AU Triumph fescue were 142.1g and 412.59kg/ha, respectively. However, lamb ADG started to decline and remained low when they were transferred from AU Triumph to Tifton 44 bermudagrass resulting in a low ADG and lamb gain per hectare of only 18.2g and 84.09kg/ha, respectively. In contrast, Tifton 44 yielded higher post grazing residual DM, suggesting that the decline in performance of the lambs grazing Tifton 44 to be related to poor forage quality rather than availability. The results indicate that low nutritive value of Tiftton 44 bermudagrass is a limiting factor to lamb production in the forage system studied. To prevent the observed decline in lamb performance, it might be necessary to fertilize Tifton 44 at a higher rate or replace it with a better quality warm season forage.

Journal Article↗

PubMed2000

A critical time intervention with mentally ill homeless men: impact on psychiatric symptoms.

We describe the impact of a psychosocial intervention, critical time intervention (CTI), on the cardinal symptom dimensions of schizophrenia, namely negative, positive, and general psychopathology. Ninety-six men with schizophrenia and other psychotic disorders who were discharged from a homeless shelter were randomly assigned to receive either CTI or usual services only. CTI is a time-limited intervention designed to enhance continuity of care during the transition from institution to community. Symptom severity at baseline and at 6 months was assessed using the Positive and Negative Syndrome Scale. Using data on 76 subjects for whom we have complete symptom data, we assessed the impact of CTI on change in symptoms. The results suggest that CTI was associated with a statistically significant decrease in negative symptoms at the 6-month follow-up, reflecting modest clinical improvement. There was no significant effect on positive or general psychopathology symptoms.

Adult↗

PubMed2000

Risk factors for homelessness among indigent urban adults with no history of psychotic illness: a case-control study.

OBJECTIVES: This study identified risk factors for homelessness among indigent urban adults without dependent children and with no history of psychotic illness. METHODS: We conducted a matched case-control study, stratified by sex, of 200 newly homeless men and women and 200 indigent men and women with no history of homelessness. Newly homeless case subjects were recruited from shelter assessment centers in New York City. Never-homeless control subjects, selected from public assistance centers, were single adults applying for home relief. Control subjects were matched with case subjects according to ethnicity, age, and sex. Trained interviewers employed standardized research instruments to probe 3 domains of risk factors: symptom severity and substance use disorder, family support and functioning, and prior use of services. RESULTS: Significant interaction effects by sex were present for symptom severity, heroin use disorder, and prior service use. Greater numbers of the homeless of both sexes lacked a high school diploma and had less income from all sources, including from their families, than of the never homeless. CONCLUSIONS: Newly homeless men and women with no history of psychotic illness differed from their never-homeless counterparts in the 3 domains investigated, but socioeconomic factors were also important.

Adolescent↗

PubMed1998

Human immunodeficiency virus sexual risk reduction in homeless men with mental illness.

BACKGROUND: The spread of human immunodeficiency virus infection to impaired groups has intensified the challenge for its prevention; control of the epidemic now requires behavioral change among persons with limited ability to sustain attention and learn. In this randomized clinical trial, we tested an intervention to reduce sexual risk behaviors among homeless men with severe mental illness. METHODS: Men were recruited from a psychiatric program in a homeless shelter. Of 116 eligible men, 97 (83.6%) participated. Most were African American and had a chronic psychotic disorder and a comorbid substance use disorder. Participants were assigned to a 15-session experimental group intervention or to a 2-session control intervention and observed for 18 months. The 59 participants sexually active before the trial were the main target of the intervention. Sexual risk behavior was the primary outcome. RESULTS: Among the 59 sexually active men, follow-up data were obtained on 59 (100%) for the initial 6-month follow-up and on 56 (95%) for the remainder of the 18-month follow-up. The mean score on a sexual risk index for the experimental group was 3 times lower than for the control group (1.0 vs 3.1; P=.01) during the initial 6-month follow-up and 2 times lower during the remainder of the 18-month follow-up. CONCLUSIONS: This intervention successfully reduced sexual risk behaviors of homeless men with mental illness. The effect diminished over 18 months but did not disappear. Similar approaches may be effective in other impaired high-risk groups.

Behavior Therapy↗

PubMed1998

Childhood experiences and current adjustment of offspring of indigent patients with schizophrenia.

OBJECTIVE: This study reports the childhood experiences, current life situation and level of adjustment, and prior mental health service use of offspring of indigent people with schizophrenia. METHODS: Sixty-eight patient-parents were asked for consent for researchers to contact their adolescent and adult offspring. Thirty-nine consenting offspring were interviewed with an assessment battery that included measures of current occupational and social functioning, psychiatric status, and mental health service use. RESULTS: Interviewed offspring were raised in an average of three different settings from birth to 18 years of age. Relatives, particularly grandparents and aunts, were more likely to provide surrogate parenting than were nonkin foster parents and were more significant nurturing figures than biological parents. The typical offspring had a high school diploma, was gainfully employed, and was involved with a spouse or household partner or had a close friend. Twenty-three of the 39 offspring had children, and most were raising their children alone. Ten offspring had a diagnosis of major depression, schizoaffective disorder, or drug or alcohol abuse, but none had a diagnosis of schizophrenia. Four of the ten offspring with a psychiatric diagnosis had never been treated. CONCLUSIONS: Findings underscore the need for long-term studies of families with a parent who is a psychiatric patient. Rehabilitation efforts should include extended family who play a critical role in raising offspring during periods when patient-parents are unable to do so. Offspring should be included in efforts to educate families about schizophrenia.

Adaptation, Psychological↗

PubMed1997

Preventing recurrent homelessness among mentally ill men: a "critical time" intervention after discharge from a shelter.

OBJECTIVES: This study examined a strategy to prevent homelessness among individuals with severe mental illness by providing a bridge between institutional and community care. METHODS: Ninety-six men with severe mental illness who were entering community housing from a shelter institution were randomized to receive 9 months of a "critical time" intervention plus usual services or usual services only. The primary analysis compared the mean number of homeless nights for the two groups during the 18-month follow-up period. To elucidate time trends, survival curves were used. RESULTS: Over the 18-month follow-up period, the average number of homeless nights was 30 for the critical time intervention group and 91 for the usual services group. Survival curves showed that after the 9-month period of active intervention, the difference between the two groups did not diminish. CONCLUSIONS: Strategies that focus on a critical time of transition may contribute to the prevention of recurrent homelessness among individuals with mental illness, even after the period of active intervention.

Adult↗

PubMed1996

Restoration of the transcription activation function to mutant p53 in human cancer cells.

The p53 tumor suppressor gene product is a sequence-specific transcription activator frequently mutated in a variety of human malignancies. Typically, tumor-derived p53 missense mutants are defective in DNA binding and this is likely to result in a failure to active p53-regulated genes. Hence, restoring function to mutant p53 represents an attractive target to develop a novel cancer chemotherapeutic agent. We now show that a small chemically modified peptide derived from p53 restores sequence-specific DNA binding to a subset of p53 mutants. Moreover, when microinjected into human colon carcinoma cells this peptide restores the transcription activation function to endogenous mutant p53 protein. This is the first example showing that a small peptide molecule can reverse the effect of several inactivating missense mutations and restore protein function.

Amino Acid Sequence↗

PubMed1996

Prognostic significance of biomarkers (c-erbB-2, p53, proliferating cell nuclear antigen, and DNA content) in salivary duct carcinoma.

Salivary duct carcinoma (SDC), a rare neoplasm of the major salivary glands, is a high-grade carcinoma with a predilection for elderly men. The authors investigated the prognostic role of p53, c-erbB2, proliferating cell nuclear antigen (PCNA), and DNA flow cytometry in a pathobiological evaluation of a cohort of 30 patients with these neoplasms. The patient group comprised 24 men and 6 women, with ages ranging from 22 to 87 years (mean = 61 years). Twenty-eight tumors were located in the parotid gland and two in the submandibular gland. Tumor size ranged from 1.0 to 8.0 cm (mean = 3.48 cm). Regional metastases were found in 73.3% (22 patients), systemic metastases in 43.3% (13 patients), and recurrences in 8 (26.6%) patients. DNA aneuploidy was found in 18 tumors (58.0%) and DNA diploidy in 12 (42%), with proliferative fractions ranging from 8.60% to 15.5 (mean = 10.6%). p53 protein nuclear immunostaining was positive in 56.6% and c-erbB2 overexpression was observed in 63% of the tumors. PCNA positivity ranged from 16.5% to 91.0%, with a mean of 49.5%. p53 immunopositivity, DNA aneuploidy, high growth, and proliferative fractions by PCNA and flow cytometry did not correlate with patient outcome. These results indicate that tumor size (P = .05), distant metastasis (P = .006), and C-erbB2 amplification (P = .04) are independent prognostic parameters in patients with salivary duct carcinoma.

Adult↗

PubMed1996

Immunization against growth hormone releasing factor or chronic feed restriction initiated at 3.5 months of age reduces ovarian response to pulsatile administration of gonadotropin-releasing hormone at 6 months of age and delays onset of puberty in heifers.

A severe or moderate suppression of serum insulin-like growth factor I (IGF-I) was induced in heifers, beginning at 104 days of age, by active immunization against growth hormone-releasing factor (GRFi) or by chronic feed restriction (RES), respectively. We hypothesized that reduced serum IGF-I results in decreased serum estradiol-17 beta (E2), which in turn delays onset of puberty. The objectives of this experiment were to determine 1) whether GRFi and RES would alter follicular development and delay onset of puberty through similar mechanisms, and 2) whether GnRH would enhance follicular growth in control, GRFi, and RES heifers at 6 mo of age. Changes in IGF-I, somatotropin, LH, FSH, and E2 were evaluated. Serum IGF-I was greater in control than in RES heifers, and was greater in both these groups than in GRFi heifers by 169 days of age. Basal LH decreased in control and RES but not in GRFi heifers from 136 to 157 days of age. During the same period, a decrease in mean FSH was detected in control but not in GRFi and RES heifers. RES decreased mean serum E2 from 148 to 183 days of age. At 6 mo of age, pulsatile administration of GnRH (5 micrograms every 2 h for 42-46 h) increased serum LH and FSH similarly across treatments but had no effect on the number of follicles > or = 8 mm in GRFi and RES heifers relative to saline treatment. Serum E2 and IGF-I in follicular fluid from follicles > or = 8 mm were increased in all GnRH-treated heifers; however, concentrations of both hormones were lower in GRFi than in control or RES heifers. The main effect of treatments on serum IGF-I was reflected in follicles < or = 7 mm; follicular fluid IGF-I was greater in control than in RES heifers and was greater in both these groups than in GRFi heifers. Serum E2 was lower in RES than in control and GRFi heifers from 253 to 281 days of age. Because of an interaction, E2 was lower in GRFi-GnRH than in control-GnRH heifers but similar in GRFi-saline and control-saline heifers. By 393 days of age, 0% of RES and 32% of GRFi heifers had reached puberty compared to 71% of control heifers. These data support our hypothesis that decreased serum IGF-I results in decreased serum E2. GRFi appears to delay puberty in heifers because decreased serum IGF-I impairs the ovary's ability to synthesize preovulatory concentrations of E2, thereby delaying stimulation of an LH surge. In contrast, RES may delay puberty by delaying follicular development at two stages: a) decreased IGF-I in follicles < or = 7 mm may delay predominant follicular growth, and b) decreased LH may delay maturation of the preovulatory follicle.

Aging↗

PubMed1995

Endocrine and ovarian responses to exogenous estradiol-17 beta in 6-month-old heifers previously immunized against growth hormone-releasing factor.

We hypothesized that estradiol-17 beta (E2) was capable of stimulating an LH surge in 6-mo-old heifers immunized against growth hormone-releasing factor (GRFi). To test this hypothesis Angus x Simmental heifers were immunized against GRF (n = 11) or human serum albumin (HSAi) (n = 6) at 113 d of age. Heifers were injected i.m. with 500 micrograms of E2 at 172 d of age. To characterize the LH response, samples were collected at frequent intervals for 1 h before and 32 h after E2. To assess ovarian responses, real-time ultrasonography was performed from d 9 to 20, and serum progesterone was evaluated from d 6 to 25 after E2, then weekly for 13 wk. Exogenous E2 stimulated (P < .001) LH surges, preceded by negative E2 feedback that decreased serum LH, in all GRFi and HSAi heifers. During the negative feedback period, serum LH was greater (P < .001), and the change in LH from before to after E2 was lower (P < .05), in GRFi than in HSAi heifers. Puberty occurred in 7/17 heifers within 66 d after receiving E2. We conclude that GRFi does not impair the release of an E2-induced LH surge, but it does decrease hypothalamo-hypophyseal sensitivity to the inhibitory effect of E2.

Animals↗

PubMed1994

Radioimmunoassays for the C-terminus of prothymosin alpha and the N-terminus of parathymosin alpha for the measurement of the levels of alpha-thymosins in human cancer.

A radioimmunoassay specific for the C-terminus of human prothymosin alpha was developed using the synthetic peptide [Cys-Aca degrees]-human prothymosin alpha (90-109)-OH coupled to KLH as antigen and the analogue [Tyr-Aca degrees]-human prothymosin alpha (90-109)-OH labelled with 125I as tracer. The radioimmunoassay measured intact prothymosin alpha, in the range of 2-100 pmol and does not cross-react with the partly homologous polypeptide parathymosin alpha. A major epitope was located in the segment 95-107. A radioimmunoassay specific for the N-terminus of human parathymosin alpha, also measuring intact parathymosin alpha in the range of 1-20 pmol and not cross-reacting with prothymosin alpha, was developed using the synthetic peptide [Cys-Aca degrees]-human parathymosin alpha (1-30)-OH as antigen coupled to KLH and the analogue [Tyr-Aca degrees]-human parathymosin alpha (1-10)-OH labelled with 125I as tracer. A major epitope was located in the segment 1-10. These radioimmunoassays, together with a previously established radioimmunoassay for the N-terminus of prothymosin alpha, permitted the identification of the molecular forms of the cross-reactive materials in both normal and neoplastic breast tissue extracts as intact prothymosin alpha and parathymosin alpha. It was also possible to reveal significantly higher levels of both alpha-thymosins in breast cancer tissue compared to the nearby healthy tissue--the mean of 14 samples was over 14-fold higher--suggesting a role of both prothymosin alpha and parathymosin alpha in cell proliferation. The reported radioimmunoassays are expected to facilitate the search for prognostic and/or diagnostic applications of these polypeptides in human cancer.

Aged↗

PubMed1994

Correlates of codisorders in homeless and never homeless indigent schizophrenic men.

We recently completed a case-control study of 100 literally homeless and 100 never homeless indigent schizophrenic men in New York City, in which concurrent substance abuse and antisocial personality disorder were widespread. In this paper we probe the correlates of 'pure' schizophrenia (single disorder, N = 60), schizophrenia and substance abuse (double disorder, N = 89), and schizophrenia, substance abuse, and antisocial personality disorder (triple disorder, N = 50), across the homeless/never homeless distinction. Subjects were recruited from a homeless shelter and mental health service programmes in Upper Manhattan. Psychologist and social worker interviewers administered the Structured Clinical Interview for DSM-III-R, I, and II and other structured instruments to explore social, family and illness history, the current illness, and aspects of treatment and family support. Codisorder subjects emerged from more disadvantaged family backgrounds, experienced greater school difficulties, began drug use in early adolescence, were more prone to hyperactivity in childhood, and were more likely to have spent time in jail. While codisorder groups did not differ on key aspects of schizophrenia, the triple disorder group was found to suffer from a more severe form of substance abuse than double disorder subjects, associated with an earlier age of onset and abuse of a wider array of substances. The widespread prevalence of codisorders among indigent schizophrenic men has major significance for clinical psychiatry. Study of the correlates of codisorders has revealed important differences in social, family, and illness history which may guide the development of more effective treatments and improved service delivery.

Adolescent↗

PubMed1994

Membrane topology of the rat kidney neutral and basic amino acid transporter.

A recently cloned rat kidney protein (NBAT) mediates the sodium-independent transport of neutral as well as basic amino acids and cystine when expressed in Xenopus laevis oocytes. The human equivalent of this transporter may be the one that is defective in cystinuria. Immunocytochemical studies have indicated that NBAT is primarily localized in the brush border membranes of rat kidney and intestinal epithelial cells, a localization consistent with its proposed role in amino acid transport. Two contrasting topological models have been proposed for NBAT: a four membrane-spanning domain (MSD) Nin-Cin model and a single MSD Nin-Cout model. We have investigated the topology of this membrane protein using two different approaches. One method was an immunofluorescent labeling technique in which intact or membrane-permeabilized cells expressing NBAT were probed with antibodies directed against putative extracellular and intracellular domains of the protein. In the second method, fragments generated by limited surface proteolysis of intact brush border membrane vesicles were subjected to immunoblot analysis using several site-specific antibodies. Both approaches yielded results consistent with a four MSD Nin-Cin topological model for NBAT.

Amino Acid Sequence↗

PubMed1994

Risk factors for homelessness among schizophrenic men: a case-control study.

OBJECTIVES: To identify risk factors for homelessness among the severely mentally ill, we conducted a case-control study of 100 indigent schizophrenic men meeting criteria for literal homelessness and 100 such men with no homeless history. METHODS: Subjects were recruited from shelter, clinic, and inpatient psychiatric programs in Upper Manhattan. Clinical interviewers employed standardized research instruments to probe three domains of risk factors: severity of mental illness, family background, and prior mental health service use. RESULTS: Homeless subjects showed significantly higher levels of positive symptoms, higher rates of a concurrent diagnosis of drug abuse, and higher rates of antisocial personality disorder. Homeless subjects experienced greater disorganization in family settings from birth to 18 years and less adequate current family support. Fewer homeless subjects than subjects in the never-homeless comparison group had a long-term therapist. These differences remained when demographic variables were adjusted statistically. CONCLUSIONS: Homeless schizophrenic men differed from their domiciled counterparts in all three domains we investigated; family background, nature of illness, and service use history. Findings are discussed in relation to policy and programs for the severely mentally ill.

Adolescent↗

PubMed1993

Characterization of the rat neutral and basic amino acid transporter utilizing anti-peptide antibodies.

High-titer, site-specific antibodies have been produced against the rat kidney broad-spectrum, sodium-independent neutral and basic amino acid transporter (NBAA-Tr) whose cDNA we cloned earlier. These antibodies have allowed us to characterize the transporter protein in normal rat tissues and in various cellular and in vitro expression systems. Western analysis detected 84- to 87-kDa glycosylated species enriched in rat renal and jejunal epithelial cell brush border membranes. In vitro translation of NBAA-Tr complementary RNA in the rabbit reticulocyte lysate system yielded a 78-kDa protein, a molecular mass that was predicted by the amino acid sequence deduced from the cloned cDNA. Translation in the presence of rough microsomal membranes yielded a glycosylated 89-kDa species. Glycosylated 87- to 89-kDa species were also expressed in Xenopus oocytes microinjected with NBAA-Tr complementary RNA and in COS-7 cells transfected with NBAA-Tr cDNA. Localization of NBAA-Tr in renal and intestinal brush border membranes is consistent with its proposed role in transepithelial transport of amino acids.

Amino Acid Sequence↗

PubMed1993

Follow-up of chronically homeless mentally ill men.

OBJECTIVE: To supply information on the efficacy of on-site day treatment for homeless mentally ill men in shelters, the authors followed up homeless mentally ill men 18 months after placement in community housing. METHOD: The 42 subjects had been evaluated before and 6 months after entering an on-site day treatment program. The authors reinterviewed 34 of these patients again 1 year after the first follow-up to determine housing status, hospitalization, aftercare, criminal justice contacts, income, and employment. RESULTS: By the 18-month follow-up the positive effects of the program at 6 months had deteriorated; 44% of the men had returned to shelters at some point during the follow-up period, and the number of men with criminal justice contacts had increased to a proportion exceeding that before the program. A concurrent diagnosis of substance abuse increased the risk of homelessness during follow-up. CONCLUSIONS: These findings underscore the need for innovative treatment and support services for the homeless mentally ill who have concurrent substance abuse.

Adult↗

PubMed1991

Type-specific and cross-reactive epitopes in human papillomavirus type 16 capsid proteins.

Genital human papillomavirus (HPV) 16 infection is frequently associated with cancer of the uterine cervix, as well as with precancerous lesions. In order to generate serologic reagents which might be useful in the diagnosis of HPV 16 infection, rabbit polyclonal and mouse monoclonal antisera were raised to carboxy terminal peptides from the HPV 16 L1 and L2 open reading frames (ORFs). Anti-L1 and -L2 peptide sera recognized HPV 16 L1 and L2 fusion proteins in Western blots and by immunoprecipitation. In Western blot analysis of L1 proteins from different HPV types, antisera to the L1 peptide reacted only with HPV 16, thus identifying an HPV 16 type-specific linear epitope. Anti-L2 peptide sera reacted with L2 fusion proteins from HPVs 6 and 16, but not from BPV, thus identifying a partially cross-reactive epitope in the HPV 16 L2. Computer analysis of carboxy terminal amino acid sequences of the L1 and L2 ORFs of multiple HPV types supported the Western blot findings. Despite the HPV 16 type specificity found in Western blots, anti-L1 peptide sera identified nuclear antigen by immunocytochemistry in cervical biopsies infected with HPV 16, as well as other genital HPV types. Anti-L2 peptide sera failed to recognize antigen in infected tissue.

Amino Acid Sequence↗