Actin-binding protein profilin1 is an important determinant of cellular phosphoinositide control.

Membrane polyphosphoinositides (PPIs) are lipid-signaling molecules that undergo metabolic turnover and influence a diverse range of cellular functions. PPIs regulate the activity and/or spatial localization of a number of actin-binding proteins (ABPs) through direct interactions; however, it is much less clear whether ABPs could also be an integral part in regulating PPI signaling. In this study, we show that ABP profilin1 (Pfn1) is an important molecular determinant of the cellular content of PI(4,5)P2 (the most abundant PPI in cells). In growth factor (EGF) stimulation setting, Pfn1 depletion does not impact PI(4,5)P2 hydrolysis but enhances plasma membrane (PM) enrichment of PPIs that are produced downstream of activated PI3-kinase, including PI(3,4,5)P3 and PI(3,4)P2, the latter consistent with increased PM recruitment of SH2-containing inositol 5' phosphatase (SHIP2) (a key enzyme for PI(3,4)P2 biosynthesis). Although Pfn1 binds to PPIs in vitro, our data suggest that Pfn1's affinity to PPIs and PM presence in actual cells, if at all, is negligible, suggesting that Pfn1 is unlikely to directly compete with SHIP2 for binding to PM PPIs. Additionally, we provide evidence for Pfn1's interaction with SHIP2 in cells and modulation of this interaction upon EGF stimulation, raising an alternative possibility of Pfn1 binding as a potential restrictive mechanism for PM recruitment of SHIP2. In conclusion, our findings challenge the dogma of Pfn1's binding to PM by PPI interaction, uncover a previously unrecognized role of Pfn1 in PI(4,5)P2 homeostasis and provide a new mechanistic avenue of how an ABP could potentially impact PI3K signaling byproducts in cells through lipid phosphatase control.

An update on genetically encoded lipid biosensors.

Specific lipid species play central roles in cell biology. Their presence or enrichment in individual membranes can control properties or direct protein localization and/or activity. Therefore, probes to detect and observe these lipids in intact cells are essential tools in the cell biologist's freezer box. Herein, we discuss genetically encoded lipid biosensors, which can be expressed as fluorescent protein fusions to track lipids in living cells. We provide a state-of-the-art list of the most widely available and reliable biosensors and highlight new probes (circa 2018-2021). Notably, we focus on advances in biosensors for phosphatidylinositol, phosphatidic acid, and PI 3-kinase lipid products.

Female circumcision: a report of four adolescents.

PIP: Although female circumcision is not traditionally performed in the US, health professionals must consider the possibility when seeing a female patient from central Africa that she may have been circumcised. A genital examination should therefore be part of such women's routine health maintenance. Pertinent genitourinary symptoms which may be secondary to the circumcision should be elicited. When pelvic exam is difficult or impossible in a patient, pelvic sonography can supplement rectal exam when pelvic pathology is suspected. Some adolescents may desire reconstructive surgery, while others will want only symptomatic treatment if complications arise. It is also important to create a comfortable environment in which relevant psychosocial issues may be discussed as the young women become acculturated into Western society. Four cases of recently immigrated, circumcised adolescent females from Somalia are reported. It is not illegal to perform female circumcision in the US, but efforts are being made to create and implement such legislation. When parents present requesting a circumcision for their daughter, they must be given information about the risks and complications of the procedure and its outcome. Culturally sensitive counseling should be offered to help the family make its decision.^ieng

Diabetic mastopathy: a clinicopathologic study in palpable and nonpalpable breast lesions.

Diabetic mastopathy is a distinct clinicopathologic entity with specific histopathologic characteristics which include keloidal fibrosis, epithelioid fibroblasts, widespread periductal/lobular lymphocytic infiltration, and widespread perivascular lymphocytic infiltration. We report the clinical and histopathologic breast tissue findings of 20 patients with diabetes mellitus as compared to 20 age-matched controls. The control patients also were matched for diseases other than diabetes mellitus. All patients with diabetes mellitus showed at least one of the histologic findings of diabetic mastopathy: 13 patients (65%) showed all four histopathologic characteristics; one patient showed three; one patient showed two; and five patients showed one feature. The 20 control patients did not demonstrate any of the four histopathologic features of diabetic mastopathy. We confirm previously reported findings of diabetic mastopathy presenting as palpable breast masses in insulin-dependent diabetics. However, we also suggest that diabetic mastopathy should be expanded to include the histopathologic findings characteristic in diabetic patients with nonpalpable mammographic abnormalities and breast tissue distant to the site of involvement by carcinoma.

Computerized relational database for monitoring clozapine therapy.

The use of a computerized relational database to satisfy the patient-monitoring requirements of clozapine's manufacturer at an Oregon state psychiatric facility is described. The pharmacy department designed a computerized system to efficiently manage the patient-monitoring requirements of clozapine's manufacturer. A relational database program allows information in database files to be readily retrieved and organized into standardized or customized reports. These reports provide white blood cell (WBC) counts to the drug's manufacturer, patient discharge information to other clozapine providers, psychiatric test results to treating physicians, financial data to hospital administration, and other key data related to the facility's clozapine treatment system. The computerized system minimized the additional workload required to dispense clozapine, decreased the cost of clozapine by $234,441 compared with the cost under the closed distribution system, and provided for comprehensive clinical monitoring. Between May 1991 and October 1992, 168 clozapine recipients were monitored; pharmacists notified physicians about 86 patients not meeting WBC-count criteria. The use of a computerized relational database enabled a state psychiatric hospital to efficiently manage the burden of monitoring clozapine recipients.

Recurrent group C streptococcal tonsillopharyngitis in an adolescent.

Sore throat is a frequent complaint in the adolescent age group. Beta-hemolytic Streptococcus Group C is not a commonly reported etiology of tonsillopharyngitis. This is a case report of a 14-year-old adolescent female who had repeated episodes of pharyngitis secondary to beta hemolytic streptococcus Group C.

A flow cytometric assay for intracellular nonprotein thiols using mercury orange.

The level of nonprotein thiols was assayed in individual mammalian cells using flow cytometry. Previous determinations of glutathione (GSH, the most abundant nonprotein thiol in most cells) by flow cytometry were based on UV laser excitation of fluorochromes. Because of several shortcomings of UV excitation, an assay for GSH using visible light is of interest. Selective staining of nonprotein thiols with mercury orange (a mercurial compound that binds stoichiometrically to sulfhydryl groups) was obtained by restricting the staining time. By using various drugs that affect GSH levels and overall thiol levels in cells, it was shown that GSH is the primary thiol group being stained. Thus a quick, specific technique using mercury orange has been developed for the flow cytometric determination of nonprotein thiols and preferentially for GSH in individual mammalian cells.

Cross cultural issues in adolescent medicine.

This article provides general guidelines and principles for physicians caring for adolescent patients from various cultural backgrounds. Suggestions are offered for managing the special problems presented by new immigrants. Case vignettes are liberally used to illustrate health care issues.

Subcultural differences in alcohol use among youth.

A specifically designed anonymous questionnaire concerning the use of alcoholic beverages was given to all young people in residence at the San Diego Job Corps Center. Corpsmembers (n = 335), age 16-22 years (mean 18.7 years) completed the questionnaire. There were 67 Caucasians, 65 Blacks, 111 Hispanics, 69 Indochinese, and 23 others. Eighty-five percent of the corpsmembers reported drinking alcohol 1-5 times weekly during the previous six months, and 14% reported average weekend binges of more than 20 drinks. Sixty percent of the adolescent drinkers reported medical, legal, or vocational problems as a result of their drinking. Some striking differences were noted in the drinking habits of the four major subcultural groups represented: 1) Caucasian males began serious drinking at an earlier age than Black, Hispanic or Indochinese youth; 2) more Hispanic youth than others used multiple drugs in addition to marijuana, which was commonly used by all adolescent drinkers; and 3) recently immigrated Indochinese youth indicated that they had turned to alcohol as a means of forgetting past experiences.